Itch treatment device

Abstract

Provided is a portable pruritus treatment device which is capable of achieving a sufficient antipruritic effect in lieu of a drug therapy that causes systemic symptoms, and with which a patient can repeatedly perform radiation at home.　This pruritus treatment device is characterized in having a light beam source for emitting a light beam and a light beam radiation probe for radiating the light beam, and is characterized in that the light beam emitted by the light source is percutaneously radiated from the light beam radiation probe toward sensory nerves that dominate a pruritus occurrence site of the skin or the mucosal epithelium.

Description

[Technical Field]

[0001] The present invention relates to a pruritus treatment device that treats itching by irradiating sensory nerves that innervate the area where itching occurs with light. [Background technology]

[0002] Pruritus is an unpleasant, scratching sensation on the skin that can be caused by various skin and systemic diseases. This symptom often manifests as inflammation, an allergic reaction, or a skin response to external stimuli. Examples of diseases that cause pruritus include xerosis, senile pruritus, atopic dermatitis, urticaria, refractory chronic prurigo, pruritus, renal failure, hemodialysis, diabetes, and HIV infection. In these conditions, pruritus often becomes chronic, significantly reducing the patient's quality of life (QOL).

[0003] Current treatments for itching typically involve drug therapy, such as antihistamines, steroids, and immunosuppressants. Drug therapy usually aims to alleviate symptoms and is known to be particularly effective for conditions such as atopic dermatitis and urticaria (see, for example, Patent Document 1). However, drug therapy can have side effects, especially with long-term use. For example, excessive use of steroids can cause thinning of the skin. Also, immunosuppressants increase the risk of infection.

[0004] On the other hand, ultraviolet light therapy, a physical treatment method, is known to be helpful in alleviating symptoms, especially in chronic skin diseases, but it has drawbacks such as an increased risk of skin cancer and the need for repeated visits to medical institutions for treatment.

[0005] Under these circumstances, phototherapy using infrared light (wavelengths of approximately 700-2500 nm) has been reported as a non-invasive and safe therapy. Examples include laser irradiation therapy to the itchy areas of the skin in patients with atopic dermatitis (e.g., Non-Patent Documents 1-4), and irradiation therapy near the stellate ganglion, one of the sympathetic ganglia, using low-level lasers (LLL) with near-infrared wavelengths in patients with atopic dermatitis (e.g., Non-Patent Documents 5, 6). Furthermore, a technique has been reported in which light is irradiated onto the itchy area using a portable probe device (Patent Documents 2-3). The devices described in Patent Documents 2-3 require a built-in heating means to maintain the skin contact surface in contact with the device at a specific temperature. Furthermore, Non-Patent Documents 1-6 and Patent Documents 2-3 contain no reports whatsoever regarding irradiation of the sensory nerves that innervate the area of ​​skin where itching occurs, rather than the area itself.

[0006] On the other hand, the present inventors have reported the application of LLL (Liquid Liquidambar) irritable bowel syndrome as a physical treatment method that suppresses inflammatory effects and excessive nerve activity (Patent Document 4). The light irradiation device described in Patent Document 4 is suitable for repeated irradiation by the patient themselves at home because the irradiation range is pinpoint and the device is small. [Prior art documents] [Patent Documents]

[0007] [Patent Document 1] WO2007 / 097317 publication [Patent Document 2] U.S. Patent Application Publication No. 2023 / 0173278 [Patent Document 3] U.S. Patent Application Publication No. 2012 / 0209357 Specification [Patent Document 4] Patent No. 7343708 [Non-patent literature]

[0008] [Non-Patent Document 1] Tae-Rin K. et al., Photochemistry AND Photobiology, vol 90, Issue 5, 2014 [Non-Patent Document 2] You K. et al., Experimental and Therapeutic Medicine 22: 1196, 2021 [Non-Patent Document 3] Mistica L., et al., The American Journal of Cosmetic Surgery, vol 38, Issue 3, 2021 [Non-Patent Document 4] Christian K. et al., JMIR Res Protec. 2019 Jan; 8(1): e11911 [Non-Patent Document 5] Toyofumi Hosokawa, Misako Omori, and Yasuko Kawabata, "Control of Itch with Low-Power Laser Therapy," Journal of the Japanese Society for Laser Medicine, Vol. 24, No. 1 (2003), pp. 3-10. [Non-Patent Document 6] Hirohiro Yamada, "Effect of low-power laser irradiation near the stellate ganglion," Journal of the Japanese Society for Laser Medicine, Vol. 24, No. 1 (2003), pp. 37-41. [Overview of the Initiative] [Problems that the invention aims to solve]

[0009] Therefore, there was a need to develop a portable pruritus treatment device that could achieve sufficient relief from itching and could be repeatedly used by the patient at home, as an alternative to drug therapy that causes systemic symptoms. [Means for solving the problem]

[0010] In view of the above situation, the inventors conducted diligent research and found that by transcutaneously irradiating sensory nerves that innervate the itchy area of ​​the skin or mucous membrane epithelium with light, the excessive activation of sensory nerves that cause itching can be directly suppressed, thereby efficiently treating or preventing itching. This led to the completion of the present invention. Therefore, the present invention provides the following: [1] A pruritus treatment device comprising a light source that emits light rays and a light irradiation probe that irradiates said light rays, characterized in that the light rays emitted by the light source are irradiated transcutaneously from the light irradiation probe toward sensory nerves that innervate the site of itching in the skin or mucosal epithelium. [2] The average power of the light emitted from the light irradiation probe is 32 mW to 26665 mW, and the average power density, obtained by dividing the average power by the light irradiation area, is 14 mW / cm². 2 ~11748 mW / cm² 2 The energy, which is the amount of light, is 5.8 J to 4800 J per irradiation, and the energy density, which is the energy divided by the irradiation area of ​​the light, is 2.6 J / cm² per irradiation. 2 ~2115J / cm 2 , and / or the pruritic treatment device according to [1], wherein the wavelength is 750 nm to 850 nm. [3] The pruritus treatment device according to [1] or [2], wherein the sensory nerve to be irradiated with light is the median nerve, sacral nerve, or sciatic nerve. [4] The itching treatment device according to any one of [1] to [3], characterized in that the light source is built into the light irradiation probe and the device is portable. [Effects of the Invention]

[0011] The pruritus treatment device of the present invention can efficiently and safely treat or prevent itching by transcutaneously irradiating sensory nerves that innervate the area where itching occurs with light. Furthermore, because the pruritus treatment device of the present invention is portable, patients can repeatedly irradiate themselves at home or while out and about, making it highly practical. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic diagram showing a typical embodiment of the pruritus treatment device of the present invention. [Figure 2] Figure 2 is a schematic diagram showing a typical embodiment of the pruritus treatment device of the present invention. [Figure 3]Figure 3 is a graph showing the relationship between the depth of sensory nerves from the skin surface and energy density in the vicinity of approximately 0.025 cm radius from the center of the light-irradiated area. [Figure 4A] Figure 4A shows the therapeutic effect of the pruritus treatment device of the present invention on mice that developed acute itching after being irradiated with light and then administered an pruritic substance (histamine (His)). [Figure 4B] Figure 4B shows the therapeutic effect of the pruritus treatment device of the present invention on mice that developed acute pruritus after being irradiated with light and then administered an pruritic substance (chloroquine (CQ)). [Figure 4C] Figure 4C shows the therapeutic effect of the pruritus treatment device of the present invention on mice that developed acute pruritus after being irradiated with light and then administered an pruritic substance (serotonin (5-HT)). In Figures 4A-4C, the sham irradiation group is the group that underwent only experimental procedures equivalent to laser irradiation, without outputting a laser. [Figure 5A] Figure 5A shows the changes in the pruritus treatment effect depending on the irradiation site in mice that developed acute pruritus after being irradiated with light using the pruritus treatment device of the present invention and then administered an pruritic substance (histamine (His)). [Figure 5B] Figure 5B shows the changes in the pruritus treatment effect depending on the irradiation site in mice that developed acute pruritus after being irradiated with light using the pruritus treatment device of the present invention and then administered an pruritus-inducing substance (chloroquine (CQ)). [Figure 5C] Figure 5C shows the change in the effectiveness of treating pruritus depending on the irradiation site in mice that developed acute pruritus after being irradiated with light using the pruritus treatment device of the present invention and then administered an pruritic substance (serotonin (5-HT)). In Figures 5A to 5C, the sham irradiation group is the group in which no laser was emitted, and only experimental procedures equivalent to laser irradiation were performed. Also, in each figure, "pruritic substance administration site" is synonymous with the site where pruritus occurred. [Figure 6A] Figure 6A shows experimental condition 1 in Example 4. The horizontal axis, "Average power," represents the average power. The same applies to Figures 6B and subsequent figures. [Figure 6B]Figure 6B shows experimental condition 2 in Example 4. [Figure 7A] Figure 7A shows the tendency for the pruritic effect to increase in an average power-dependent manner in mice that developed acute pruritus after being irradiated with light using the pruritic treatment device of the present invention and then administered an pruritic substance (histamine (His)). [Figure 7B] Figure 7B shows the tendency for the pruritic effect to increase in an average power-dependent manner in mice that developed acute pruritus after being irradiated with light using the pruritic treatment device of the present invention and then administered an pruritic substance (chloroquine (CQ)). [Figure 7C] Figure 7C shows the tendency for the pruritic effect to increase in an average power-dependent manner in mice that developed acute pruritus after being irradiated with light using the pruritic treatment device of the present invention and then administered an pruritic substance (serotonin (5-HT)). In Figures 7A to 7C, irradiation was performed using experimental conditions 1 from Example 4. In each figure, x represents the average power and y represents the number of scratching movements per 30 minutes. [Figure 8] Figure 8 shows the relationship between energy and the number of scratching motions when irradiation was performed using experimental condition 2 in Example 4. [Modes for carrying out the invention]

[0013] The pruritus treatment device of the present invention treats or prevents pruritus by suppressing the hyperactivity of sensory nerves that innervate the area where pruritus occurs, by irradiating them with a predetermined light beam.

[0014] [Itch treatment device] Embodiments of the pruritus treatment device of the present invention will be described with reference to the drawings. As shown in Figure 1, a typical pruritus treatment device 1 of this embodiment is a medical device for treating or preventing pruritus by transcutaneously irradiating light beams towards the sensory nerves that innervate the site of pruritus. The pruritus treatment device comprises a light beam irradiation probe 2 that emits light beams, a light beam source 3, a probe cable 4 that connects the light beam source and the light beam irradiation probe, and a main body 5 that houses the light beam source.

[0015] In the pruritus treatment device of the present invention, pruritus can be treated or prevented by applying the light irradiation probe 2 to the surface of the skin or mucosal epithelium (hereinafter sometimes simply referred to as "skin") in the area where sensory nerves that innervate the pruritus are located, and irradiating it with light. Figure 1 shows how the light is guided by the probe cable 4, and the main unit is equipped with a power supply (not shown). Furthermore, as shown in Figure 2, the pruritus treatment device can also be configured to have the light source and power supply 6 built into the light irradiation probe 2, making it portable and allowing for the treatment or prevention of pruritus even when out and about. Many patients with pruritus lead normal daily lives like healthy individuals without hospitalization or outpatient visits, so a portable treatment or prevention device is convenient as it can be used when needed.

[0016] To enhance the safety of light irradiation, the tip of the light irradiation probe preferably has a structure that allows the tip to contact the skin surface and prevents diffusely reflected light from the skin from leaking to the outside. The tip and vicinity of the light irradiation probe preferably have a structure that enables irradiation only when the light irradiation probe is in proper contact with the skin at the irradiation site. Such a structure is, for example, a device equipped with a sensor that detects contact with the skin and a control calculation unit that controls the ON / OFF of light irradiation based on the detection result. One possible side effect of light exposure is burns caused by an increase in skin temperature. To avoid burns, pulsed irradiation, which involves intermittently irradiating the skin with light while maintaining the energy and energy density of the light, can mitigate the rise in skin temperature. In this case, a repetition frequency of 0.5 to 10 Hz is preferable. Furthermore, it is preferable to have a structure that uses a fan or compressor as an air source to blow air onto the skin through a flow path, thereby lowering the temperature through forced convection.

[0017] [Area of ​​light irradiation] In this invention, the light irradiation site is the skin surface and is not particularly limited as long as the light irradiation field hits a sensory nerve. Preferably, it is the skin surface where a sensory nerve runs below the center of the light irradiation, and where there are no obstacles such as bone between the sensory nerve and the skin surface. Examples of mucosal epithelium include the mucosal epithelium of the oral cavity, cornea (or eyeball), nasal cavity, external auditory canal, anus, and genitals. In this invention, in addition to the irradiation site, the itching site itself may also be irradiated. Depending on the irradiation conditions, the cause of the itching, etc., irradiating both the above-mentioned irradiation site and the itching site may yield a higher therapeutic effect compared to irradiating the above-mentioned irradiation site alone or the itching site alone. It is preferable to irradiate the skin with light by applying the light irradiation probe from directly above the skin at the irradiation site (i.e., at an angle of approximately 90 degrees to the skin at the irradiation site).

[0018] [Sensory nerves] In this specification, "sensory nerve" encompasses all human "sensory nerves" as used in this field. That is, it includes all afferent or sensory (perceptual) nerve fibers that are classified as part of the somatic nervous system within the peripheral nervous system and have the function of transmitting nerve signals (excitations) generated from sensory receptors to the central nervous system.

[0019] Specifically, the sensory nerves targeted are those located at a depth within the range of light rays. If the sensory nerve is located quite deep from the skin surface, the light rays may not reach the sensory nerve at all, or the required energy of the light rays may not reach the sensory nerve, resulting in the desired therapeutic efficiency not being achieved or being reduced. Therefore, it is preferable that the targeted sensory nerves run relatively close to the skin surface. Since the depth from the skin surface to the sensory nerve varies among individuals, it is preferable that the mean ± standard deviation of the depth of the sensory nerve is within the range of approximately 30 mm or less, preferably in the range of approximately 4 mm to approximately 30 mm, more preferably in the range of approximately 4 mm to approximately 20 mm, and even more preferably in the range of approximately 4 mm to approximately 10 mm. Examples of such sensory nerves include the human median nerve (mean 4.9 mm), the human sciatic nerve (mean 18.6 mm), and the human sacral nerve (mean 23.7 mm).

[0020] Of course, the target human sensory nerves are not limited to those mentioned above; any sensory nerve whose depth from the skin surface meets the above conditions can be targeted. For example, the brachial plexus other than the human median nerve (e.g., ulnar nerve, radial nerve, musculocutaneous nerve, axillary nerve) or the human trigeminal nerve generally meet this depth requirement. Also, while sensory nerves located within the vertebrae from the neck to the lumbar spine are usually more than 50 mm from the skin surface, the human cervical plexus on the ventral side of the vertebrae (e.g., lesser occipital nerve, greater occipital nerve, greater auricular nerve, transverse cervical nerve, supraclavicular nerve, phrenic nerve, superior root of the supraorbital nerve, inferior root of the supraorbital nerve) meets the depth requirement at approximately 4 mm to 30 mm depending on the location. The vagus nerve, which plays a role in transmitting sensation behind the auricle, is also a target.

[0021] Furthermore, other sensory nerves that transmit sensation in the arm or shoulder besides the human median nerve include the superior lateral brachial cutaneous nerve, posterior brachial cutaneous nerve, inferior lateral brachial cutaneous nerve, posterior antebrachial cutaneous nerve, dorsal digital nerve, medial brachial cutaneous nerve, intercostal brachial nerve, and medial antebrachial cutaneous nerve. Other sensory nerves that transmit sensation in the legs besides the human sciatic nerve include the iliohypogastric nerve, ilioinguinal nerve, pudenofemoral nerve, pudendal nerve, saphenous nerve, femoral nerve, obturator nerve, common peroneal nerve, deep peroneal nerve, superficial peroneal nerve, medial dorsal cutaneous nerve of the foot, intermediate dorsal cutaneous nerve of the foot, lateral dorsal cutaneous nerve of the foot, sural nerve, dorsal digital nerve of the foot, dorsal digital nerve, superior gluteal nerve, tibial nerve, medial sural cutaneous nerve, lateral sural cutaneous nerve, posterior femoral cutaneous nerve, medial plantar nerve, lateral plantar nerve, common plantar digital nerve, and proper plantar digital nerve.

[0022] The sensation of the mucosal epithelium of the oral cavity, cornea (or eyeball), and external auditory canal is innervated by the human trigeminal nerve, and the depth from these mucosal epitheliums to the human trigeminal nerve is generally in the range of approximately 4 mm to 30 mm, satisfying the depth conditions mentioned above. In addition, the sensation of the mucosal epithelium of the nasal cavity is innervated by the human posterior nasal nerve, and the sensation of the mucosal epithelium of the anus is innervated by the human pudendal nerve, and the depth from the mucosal epithelium of the nasal cavity to the human posterior nasal nerve, and the depth from the mucosal epithelium of the anus to the human pudendal nerve are both generally in the range of approximately 4 mm to 30 mm.

[0023] [Relationship between the site of itching and the site of light irradiation] The relationship between the site of itching and the site of light irradiation is explained below. When the itching occurs in areas such as the neck, occipital neck, shoulders, upper arms, forearms, and / or hands, the sensory nerves to be irradiated with light are preferably brachial nerves such as the human median nerve. When viewed from the body surface, it is effective to irradiate from the base of the upper limb to the entire upper limb. If the itching occurs in an area such as the lower back to the toes, the sensory nerve to be irradiated with light is preferably the human sciatic nerve. From the perspective of the body surface, irradiating the lower back and lower limbs is effective. If the itching occurs in areas such as the lower back and posterior thigh, and / or the lower limbs and feet, the sensory nerve to be irradiated with light is preferably the human sacral nerve. From the perspective of the body surface, it is effective to irradiate the pelvis, sacral foramina, etc. If the site of itching is, for example, the body wall, the sensory nerves to be irradiated with light include the intercostal nerves, subcostal nerves, iliohypogastric nerves, and ilioingual nerves.

[0024] [Light irradiation conditions] The irradiation conditions for using the pruritus treatment device in the present invention preferably include any one or more of the following light irradiation conditions (excluding the wavelength condition) in order to obtain a desired therapeutic effect on pruritus, and more preferably include all the conditions. That is, the average power of the light irradiated from the light irradiation probe is 32 mW to 26665 mW, and the average power density obtained by dividing the average power by the irradiation area of the light (for example, 2.27 cm 2 ) is 14 mW / cm 2 ~11748 mW / cm 2 , the energy which is the light dose is 5.8 J to 4800 J per single irradiation (for example, 180 seconds), and the energy density obtained by dividing the energy by the irradiation area of the light is 2.6 J / cm 2 ~2115 J / cm 2 . The above average power, average power density, energy, and energy density of the light are values calculated from the average value ± standard deviation of the depth of sensory nerves including the human median nerve, human sciatic nerve, and human sacral nerve.

[0025] In another embodiment, the irradiation conditions preferably include any one or more of the following light irradiation conditions, and more preferably include all the conditions. That is, the average power of the light irradiated from the light irradiation probe is 28.6 mW to 19471 mW, and the average power density obtained by dividing the average power by the irradiation area of the light (for example, 2.27 cm 2 ) is 13 mW / cm 2 ~8578 mW / cm 2 , the energy which is the light dose is 5.1 J to 3505 J per single irradiation (for example, 180 seconds), and the energy density obtained by dividing the energy by the irradiation area of the light is 2.6 J / cm 2 ~1544 J / cm 2 . The above conditions such as the average power are values calculated from the average value ± 20% of the depth of sensory nerves including the human median nerve, human sciatic nerve, and human sacral nerve.

[0026] In yet another embodiment, the irradiation conditions preferably include one or more of the following light irradiation conditions, and more preferably include all of them. In other words, the average power of the light emitted from the light irradiation probe is 32.5 mW to 10369 mW, and the average power is measured over the light irradiation area (for example, 2.27 cm²). 2 The average power density, when divided by ), is 14 mW / cm². 2 ~4568 mW / cm² 2 The energy, which is the amount of light, is 5.9 J to 1866 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 2.6 J / cm² per irradiation. 2 ~822J / cm 2 The above conditions, such as average power, are calculated from the average value ± 10% of the depth of sensory nerves, including the human median nerve, human sciatic nerve, and human sacral nerve.

[0027] Furthermore, if the energy or energy density is close to the upper limit of the above range, burns may occur on the skin, but this can be dealt with by taking appropriate measures, such as those described in [Irradiation Method].

[0028] [Wavelength range] The wavelength of 808 nm used in the evaluation tests of the examples described below falls within the near-infrared region of 700 nm to 900 nm. As shown in Journal of Physics D: Applied Physics, 2005, 38, 2543-2555, the permeability to living organisms is equivalent in the near-infrared region, and therefore equivalent effectiveness exists in the 700 nm to 900 nm range as well. Furthermore, the absorbance spectrum of cytochrome C oxidase, which has been reported to be involved in the mechanism of action of phototherapy, has been reported to be equivalent in the 780 nm to 850 nm range, as shown in Journal of Biological Chemistry, 2005; 280(6): 4761-4771. Based on the above, the wavelength in the present invention is preferably 700 nm to 900 nm, more preferably 780 nm to 850 nm, and even more preferably 788 nm to 828 nm.

[0029] [Specific light irradiation conditions for sensory nerves] Detailed studies of light irradiation conditions for the human median nerve, human sciatic nerve, and human sacral nerve revealed that light irradiation conditions applicable to any of these sensory nerves preferably include one or more of the following conditions, and more preferably include all of them. The average power of the light ray is 9.7mW to 39998mW, and the average power is measured against the area of ​​light ray irradiation (for example, 0.785cm²). 2 The average power density, when divided by ), is 12 mW / cm². 2 ~50953mW / cm 2 The energy, which is the amount of light, is 0.3 J to 23999 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 0.4 J / cm² per irradiation. 2 ~30572J / cm 2 The wavelength is 750-850 nm. The above conditions, such as average power, are values ​​calculated from the mean ± standard deviation of the depth of sensory nerves, including the human median nerve, human sciatic nerve, and human sacral nerve.

[0030] Furthermore, the preferred light irradiation conditions for each of the sensory nerves of the human median nerve, human sciatic nerve, and human sacral nerve preferably include one or more of the following conditions, and more preferably include all of them. (A) When the sensory nerve being irradiated with light is the human median nerve (1) In one embodiment, the irradiation conditions are such that the average power of the light beam is 9.7 mW to 63.4 mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 0.785 cm²). 2 The average power density, when divided by ), is 12 mW / cm². 2 ~81mW / cm 2 The energy, which is the amount of light, is 0.3 J to 38 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 0.4 J / cm² per irradiation. 2 ~49J / cm 2 The wavelength is 750-850 nm. The above conditions, such as average power, are values ​​calculated from the mean ± standard deviation of the depth of the human median nerve.

[0031] (2) In another embodiment, the irradiation conditions are such that the average power of the light beam is 32.4 mW to 42.3 mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 2.27 cm²). 2 The average power density, when divided by ), is 14.3 mW / cm². 2 ~18.6 mW / cm 2 The energy, which is the amount of light, is 5.83 J to 7.61 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area, is 2.57 J / cm² per irradiation. 2 ~3.35 J / cm 2 The wavelength is 750nm to 850nm. The above conditions, such as average power, are values ​​calculated from the mean ± standard deviation of the depth of the human median nerve.

[0032] (3) In another embodiment, the irradiation conditions are such that the average power of the light beam is 28.6 mW to 48.0 mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 2.27 cm²). 2 The average power density, when divided by ), is 12.6 mW / cm². 2 ~21.1 mW / cm 2 The energy, which is the amount of light, is 5.14 J to 8.63 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area, is 2.26 J / cm² per irradiation. 2 ~3.80 / cm 2 The wavelength is 750nm to 850nm. The above conditions, such as average power, are values ​​calculated from the average depth of the human median nerve within ±20%.

[0033] (4) In yet another embodiment, the irradiation conditions are such that the average power of the light beam is 32.5 mW to 42.1 mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 2.27 cm²). 2 The average power density, when divided by ), is 14.3 mW / cm². 2 ~18.6 mW / cm 2 The energy, which is the amount of light, is 5.85 J to 7.58 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 2.58 J / cm² per irradiation. 2 ~3.34 J / cm 2The wavelength is 750nm to 850nm. The above conditions, such as average power, are values ​​calculated from the average depth of the human median nerve within ±10%.

[0034] (B) When the sensory nerve being irradiated with light is the human sciatic nerve (1) In one embodiment, the irradiation conditions are such that the average power of the light beam is 151mW to 6110mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 0.785cm²). 2 The average power density, when divided by ), is 192 mW / cm². 2 ~7784 mW / cm² 2 The energy, which is the amount of light, is 4.5 J to 3666 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 5.8 J / cm² per irradiation. 2 ~4670 J / cm 2 The wavelength is 750-850 nm. The above conditions, such as average power, are values ​​calculated from the mean ± standard deviation of the depth of the human sciatic nerve.

[0035] (2) In another embodiment, the irradiation conditions are such that the average power of the light beam is 503mW to 4073mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 2.27cm²). 2 The average power density, when divided by ), is 221 mW / cm². 2 ~1795mW / cm 2 The energy, which is the amount of light, is 90.5 J to 733 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 39.9 J / cm² per irradiation. 2 ~323J / cm 2 The wavelength is 750nm to 850nm. The above conditions, such as average power, are values ​​calculated from the average value ± standard deviation of the depth of the human sciatic nerve.

[0036] (3) In another embodiment, the irradiation conditions are such that the average power of the light beam is 531mW to 3851mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 2.27cm²). 2 The average power density, when divided by ), is 234 mW / cm². 2 ~1697 mW / cm² 2The energy, which is the amount of light, is 95.7 J to 693 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 42.2 J / cm² per irradiation. 2 ~305J / cm 2 The wavelength is 750nm to 850nm. The above conditions, such as average power, are values ​​calculated from the average value ±20% of the depth of the human sciatic nerve.

[0037] (4) In yet another embodiment, the irradiation conditions are such that the average power of the light beam is 872mW to 2347mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 2.27cm²). 2 The average power density, when divided by ), is 384 mW / cm². 2 ~1034 mW / cm² 2 The energy, which is the amount of light, is 157 J to 423 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 69.2 J / cm² per irradiation. 2 ~186J / cm 2 The wavelength is 750nm to 850nm. The above average power and other conditions are values ​​calculated from the average value ±10% of the depth of the human sciatic nerve.

[0038] (C) When the sensory nerve being irradiated with light is the human sacral nerve (1) In one embodiment, the irradiation conditions are such that the average power of the light beam is 343mW to 39998mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 0.785cm²). 2 The average power density, when divided by ), is 437 mW / cm². 2 ~50953mW / cm 2 The energy, which is the amount of light, is 10.3 J to 23999 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 13.1 J / cm² per irradiation. 2 ~30572J / cm 2 The wavelength is 750nm to 850nm. The above conditions, such as average power, are calculated from the average value ± standard deviation of the depth of the sacral nerves located in the left and right S1 to S4 sacral foramina.

[0039] (2) In another embodiment, the irradiation conditions are such that the average power of the light beam is 1140mW to 26665mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 2.27cm²). 2 The average power density, when divided by ), is 504 mW / cm². 2 ~11748 mW / cm² 2 The energy, which is the amount of light, is 206 J to 4800 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 90.7 J / cm² per irradiation. 2 ~2115J / cm 2 The wavelength is 750nm to 850nm. The above conditions, such as average power, are calculated from the average value ± standard deviation of the depth of the sacral nerves located in the left and right S1 to S4 sacral foramina.

[0040] (3) In another embodiment, the irradiation conditions are such that the average power of the light beam is 1566 mW to 19471 mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 2.27 cm²). 2 The average power density, when divided by ), is 690 mW / cm². 2 ~8578 mW / cm² 2 The energy, which is the amount of light, is 282 J to 3505 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 124 J / cm² per irradiation. 2 ~1544 J / cm² 2 The wavelength is 750nm to 850nm, and the above average power and other conditions are values ​​calculated from the average value ±20% of the sacral nerve depth.

[0041] (4) In yet another embodiment, the irradiation conditions are such that the average power of the light beam is 2940mW to 10369mW, and the average power is distributed across the irradiation area of ​​the light beam (e.g., 2.27cm²). 2 The average power density, when divided by ), is 1295 mW / cm². 2 ~4568 mW / cm² 2 The energy, which is the amount of light, is 529 J to 1866 J per irradiation (e.g., 180 seconds), and the energy density, which is the energy divided by the irradiation area of ​​the light, is 233 J / cm² per irradiation. 2 ~822J / cm 2The wavelength is 750nm to 850nm. The above average power and other conditions are values ​​calculated from the average value ±10% of the sacral nerve depth. For each sensory nerve, the irradiation conditions in (1) are particularly preferred.

[0042] For the treatment or prevention of itching, the patient may be irradiated with predetermined preferred light conditions, or the patient may be irradiated using a pruritic treatment device equipped with a light source that emits light under predetermined preferred conditions.

[0043] [ray] A laser beam excited by a semiconductor device or the like can be used as a light beam that satisfies the irradiation conditions of the present invention, namely average power, average power density, energy, energy density, and wavelength. Alternatively, an LED beam, lamp beam, or the like that satisfies the conditions of the present invention may be used. The literature (Photochemical & Photobiological Sciences 2018;17(8):1003-1017) reports on phototherapy using light sources such as lasers, LEDs, and lamps in the visible and infrared wavelength ranges in fields such as plastic surgery and dermatology.

[0044] [Type of irradiation] Irradiation should preferably be performed at a frequency of twice a day to once a week. Depending on the patient's condition, it can also be used before the onset of symptoms or when symptoms are likely to appear. The irradiation time should preferably be 3 to 60 minutes per session, more preferably 3 to 40 minutes, and even more preferably 3 to 30 minutes.

[0045] Irradiation can be either a single continuous irradiation or intermittent irradiation combining irradiation and rest periods. For continuous irradiation exceeding approximately 60 minutes, it is desirable to use intermittent irradiation to avoid causing burns to the skin. Examples of intermittent irradiation patterns include 3 minutes of irradiation followed by a 30-second pause, 1 minute of irradiation followed by a 10-second pause, 30 seconds of irradiation followed by a 5-second pause, and so on. In addition, in order to avoid the possibility of skin burns during irradiation with a high energy density, it is preferable to perform intermittent irradiation. Also, by instantaneously irradiating with high-intensity pulsed light and providing an appropriate rest time, it is possible to deliver light to sensory nerves at a depth of 30 mm or more while reducing the average power and preventing skin burns. It is also desirable to cool the irradiation site using a system that automatically sprays a cooling gas immediately after irradiation, which is provided in the light irradiation treatment device. Furthermore, in the case of laser irradiation, since the retina may be locally damaged by the thermal and focusing effects of the laser beam, it is desirable to wear protective glasses during irradiation. If the light irradiation probe of the itching treatment device has an interlock mechanism that allows irradiation only when it contacts the skin, it is possible to perform treatment without wearing protective glasses by using this mechanism.

[0046] The surface area to be irradiated is preferably about 0.5 cm 2 ~ about 6 cm 2 and more preferably 0.6 cm 2 ~ 3 cm 2 and even more preferably 0.6 cm 2 ~ 1 cm 2 is. The shape of the irradiation may be circular, elliptical, rectangular, etc.

[0047] The itching treatment device is preferably used in contact with the skin during irradiation. In the case of continuous irradiation or when it is difficult to contact the skin due to an uneven surface at the irradiation site, the itching treatment device may be used at a distance of about 1 to 10 cm, preferably about 1 to 5 cm, from the skin.

[0048] [Mode of itching] In the present invention, diseases that cause itching include, for example, atopic dermatitis, contact dermatitis, urticaria, psoriasis, prurigo, insect bites, xerosis, xerosis, senile pruritus, miliaria, seborrheic dermatitis, hand eczema, intractable chronic prurigo, pruritus, vulvar pruritus, chronic pruritus, hay fever, cutaneous mycosis, vesicular disease, cutaneous lymphoma, or itching associated with anal pruritus; itching associated with kidney disease, diabetes, chronic liver disease, HIV infection, mental illness, stress, neurogenic diseases, nerve disorders, or malignant tumors; and itching associated with hemodialysis, morphine administration, or chloroquine administration in malaria treatment. The primary target diseases are atopic dermatitis and contact dermatitis. Since systemic itching caused by atopic dermatitis or contact dermatitis often does not involve histamine receptors, drug therapy may not provide sufficient antipruritic effects. Therefore, the application of the present invention's pruritus treatment device to such diseases is expected. In some cases, conventional drug therapy can be used in combination with treatment using the present invention's pruritus treatment device. Note that central nervous system pruritus, which typically does not involve skin lesions and is caused by pruritus mediators directly binding to receptors on nerve cells in the central nervous system, such as the spinal cord and brain, is not included in the definition of pruritus according to this invention. Experimental example

[0049] [Example 1] Investigation of light ray transmittance by simulation The effectiveness of phototherapy generally depends on the amount of light in the target tissue. However, when light is irradiated onto living tissue, it undergoes repeated scattering and absorption, and the amount of light decreases exponentially depending on the distance from the skin surface (Lambert-Beer's law). Therefore, the effectiveness of phototherapy in deep tissues requires consideration of light transmission. Thus, it is effective to calculate the optimal output conditions by comparing the distance to nerves in animals used nonclinically with that of humans. For example, the distance from the skin surface of the cervical vertebrae of mice used as a pruritic model animal was approximately 8.6 mm. In contrast, when the position of the human cervical vertebrae was imaged using an ultrasound imaging device (Fujifilm Medical Co., Ltd.), it was found to be at a depth of approximately 52.8 mm (Korean J Pain. 2012 Apr; 25(2): 99-104). Therefore, since the cervical vertebrae of humans may be located deeper than those of mice, it is considered that the irradiation conditions equivalent to nonclinical settings may be smaller than those used in clinical trials. Although the structure of the skin differs between humans and rodents, the constituent components are similar. Therefore, it can be said that the light transmission depends more on the distance from the skin surface to the target tissue than on the differences between animal species.

[0050] Next, we attempted to convert non-clinical experimental conditions to clinical-equivalent conditions by verifying the amount of light transmitted using light scattering simulations based on the Monte Carlo Modeling of Light Transport in Multi-layered Tissues (hereinafter referred to as "MCML"), which utilizes the Monte Carlo method as described in Publication No. WO2022 / 019293 (Computer Methods and Programs in Biomedicine, Volume 47, Issue 2, July 1995, Pages 131-146). Specifically, we used MCML to verify transmittance with the aim of calculating how much the conditions related to light dose in non-clinical trials—average power, average power density, energy, and energy density—correspond to clinical conditions.

[0051] The conditions of MCML are described. A three-layer structure of the skin layer, fat layer, and muscle layer was fabricated, and the optical properties of each layer were set as follows. However, the numerical values are those of the skin, fat, and muscle, respectively (Phys. Med. Biol. 44 (1999) 2689-2702). Refractive index n: All are 1.4 Absorption coefficient μa: 0.15 cm -1 , 0.02 cm -1 , 0.3 cm -1 Scattering coefficient μs: 100 cm -1 , 80 cm -1 , 33 cm -1 Isotropic scattering parameter g: All are 0.85 Thickness: 0.1 cm, 0.4 cm, 2.0 cm Note that below the muscle layer, a layer with a refractive index of 1.4 extends infinitely. The light irradiation conditions were such that the beam profile showing the spatial intensity distribution was Gaussian, the irradiation radius was 0.9 cm, and the energy was 600 J. The number of photons was 10 million, and the calculations were performed in 0.05 cm units in the depth direction and the radial direction.

[0052] The results are described. Fig. 3 shows the relationship between the depth (X) of the sensory nerve and the energy density (Y) in the range of 0.025 cm radius from the center of the light irradiation site.

[0053]

Number

[0054] The energy density at a depth of 8.6 mm corresponding to the depth of the mouse cervical dorsal root ganglion was 3.64 J / cm 3 whereas the energy density at a depth of 52.8 mm corresponding to the depth of the human cervical dorsal root ganglion was 2.8×10 -5 J / cm 3Therefore, since the human cervical dorsal root ganglia are located deeper than those of mice, it is expected that the energy of light irradiated from the skin surface will be reflected and absorbed along the way, and hardly reach the target sensory nerves. On the other hand, in order to achieve the same energy density as irradiating the mouse cervical dorsal root ganglia with light irradiation to the human tibial dorsal root ganglia, approximately 130,000 times the amount of light would be required.

[0055] Here, the depths of the human median nerve, human sciatic nerve, and human sacral nerve from the skin surface were determined as follows. For the human median nerve, the distance from the skin surface to the median nerve at the wrist of the left arm was measured for 21 subjects using an ultrasound imaging device (Konica Minolta, Inc.), and the average result was 4.9 mm (standard deviation: 0.50 mm). For the human sciatic nerve, the distance from the skin surface to the point where the sciatic nerve in the left leg branches into the common peroneal nerve and the tibial nerve was measured for 12 subjects, and the average result was 18.6 mm (standard deviation: 3.93 mm). For the human sacral nerve, it has been reported that the distance from the skin surface to the sacral nerve located in the S3 sacral foramen is 22 mm (Patent Publication No. 7343708), but the distance from the skin surface to the sacral nerves located in the left and right S1-S4 sacral foramina was measured for 12 subjects, and the average result was 23.7 mm (standard deviation: 5.91 mm).

[0056] Table 1 shows the depth of each sensory nerve and the energy density calculated from Equation I.

[0057] [Table 1]

[0058] Furthermore, the energy density at a depth of 8.6 mm, which corresponds to the depth of the dorsal root ganglion in the mouse cervical spine, is 3.64 J / cm². 3 To achieve this with the human median nerve, 0.36 times the light dose is required; with the human sciatic nerve, 14.3 times; and with the human sacral nerve, 35.5 times the light dose.

[0059] [Example 2] Evaluation test of therapeutic and preventive effects of photoirradiation on pruritus To investigate the therapeutic and preventive effects of phototherapy on pruritus, animal studies were conducted. As a pruritus model, an acute pruritus test was performed using pruritic substances widely used in non-clinical studies of pruritus.

[0060] The test procedure is as follows: [Model animals used] An experiment was conducted to induce itching by intradermally administering pruritic substances to the backs of mice. Male mice, ICR, 6-9 weeks old were used. The groups were divided into four groups: 1) saline administration and sham irradiation group, 2) pruritic substance administration and sham irradiation group, 3) saline administration and laser irradiation group, and 4) pruritic substance administration and laser irradiation group, with 8 mice in each group. The pruritic substances used were histamine (His) (200 nmol / site, 50 μL), chloroquine (CQ) (200 μg / site, 50 μL), and serotonin (5-HT) (100 nmol / site, 50 μL). The sham irradiation group was a group in which only experimental procedures equivalent to laser irradiation were performed, without the output of a laser. [Laser irradiation] Laser light was applied transcutaneously to the cervical vertebrae of mice under the following irradiation conditions: Wavelength: 808nm, Average power: 0.1W, Peak power: 1W, Pulse oscillation, Pulse width: 20ms, Pulse pause time: 180ms, Frequency: 5Hz, Duty cycle: 10%, Irradiation area: 2.27cm² 2 Irradiation time: 180 seconds. Laser irradiation was performed under isoflurane inhalation anesthesia. [Evaluation Method] The effectiveness of the treatment for pruritus was evaluated by measuring the number of times mice scratched. [Experimental Techniques] (1) The cervical spine of mice under isoflurane inhalation anesthesia was irradiated with a laser. The sham irradiation group received sham irradiation. (2) After releasing the patient from anesthesia, an itch-inducing substance was administered intradermally to the back two hours after laser irradiation or sham irradiation. (3) The number of scratching movements was measured for 30 minutes. (4) Tukey's multiple comparison test was performed between all groups, with a significance level of 5%. [result] The results are shown in Figures 4A to 4C. The mean is shown as a bar graph, and the standard error is shown as an error bar. *** indicates that the p-value between groups is less than 0.001, and ### indicates that the p-value between groups is less than 0.001. In all cases of pruritic substances, the number of scratching movements in the pruritic substance administration group and the sham irradiation group increased significantly compared to the saline administration group and the sham irradiation group, confirming that the pathological condition was being induced. There was almost no change in the number of scratching movements in the saline administration group and the laser irradiation group compared to the saline administration group and the sham irradiation group, indicating that laser irradiation alone does not change the number of scratching movements. In all cases of pruritic substances, the number of scratching movements in the pruritic substance administration group and the laser irradiation group decreased significantly compared to the pruritic substance administration group and the sham irradiation group, confirming the therapeutic and preventive effects of laser irradiation on pruritus.

[0061] [Example 3] Comparative study of therapeutic and preventive effects on pruritus due to differences in the irradiation site of light. To compare the therapeutic and preventive effects on acute pruritus due to differences in the irradiation site of light, three irradiation sites were used in animals: (i) the cervical spine, (ii) the site of administration of the pruritic substance, and (iii) the site of administration of the pruritic substance and the cervical spine. As a test pruritus model, an acute pruritus test was conducted using a pruritic substance widely used in non-clinical trials of pruritus.

[0062] The test procedure is as follows: [Model animals used] An experiment was conducted to induce itching by intradermally administering pruritic substances to the backs of mice. Male mice, ICR, 6-9 weeks old were used. The groups were divided into four groups: 1) pruritic substance administration and sham irradiation group, 2) pruritic substance administration and laser irradiation to the cervical spine group, 3) pruritic substance administration and laser irradiation to the site of pruritic substance administration group, and 4) pruritic substance administration and laser irradiation to both the cervical spine and the site of pruritic substance administration group. Each group consisted of 8 mice. The pruritic substances used were histamine (His) (200 nmol / site, 50 μL), chloroquine (CQ) (200 μg / site, 50 μL), and serotonin (5-HT) (100 nmol / site, 50 μL). The sham irradiation group was a group in which only experimental procedures equivalent to laser irradiation were performed without laser output. [Laser irradiation] Laser light was applied transcutaneously to the cervical vertebrae of mice under the following irradiation conditions: Wavelength: 808nm, Average power: 0.1W, Peak power: 1W, Pulse oscillation, Pulse width: 20ms, Pulse pause time: 180ms, Frequency: 5Hz, Duty cycle: 10%, Irradiation area: 0.785cm² 2 Irradiation time: Groups 1 and 2 received 180 seconds of irradiation, while Group 3 received 180 seconds of irradiation on the cervical spine followed by 180 seconds on the site where the pruritic substance was administered (total 360 seconds). Laser irradiation was performed under isoflurane inhalation anesthesia. Isoflurane inhalation anesthesia was administered for 360 seconds in all groups. [Evaluation Method] The effectiveness of the treatment for pruritus was evaluated by measuring the number of times mice scratched. [Experimental Techniques] (1) Mice under isoflurane inhalation anesthesia were irradiated with a laser. The laser irradiation sites were either the cervical spine, the site of pruritic substance administration, or both the cervical spine and the pruritic substance administration site. The sham irradiation group was a group in which no laser was emitted, and only experimental procedures equivalent to laser irradiation were performed. (2) After releasing the patient from anesthesia, an itch-inducing substance was administered intradermally to the back two hours after laser irradiation or sham irradiation. (3) The number of scratching movements was measured for 30 minutes. (4) Tukey's multiple comparison test was performed between all groups, with a significance level of 5%. [result] The results are shown in Figures 5A to 5C. The mean is shown as a bar graph, and the standard error is shown as an error bar. * indicates that the p-value between groups is less than 0.05, ** indicates that the p-value between groups is less than 0.01, and *** indicates that the p-value between groups is less than 0.001. As is clear from Figures 5A-5C, for all pruritic substances, the number of scratching movements was significantly reduced in the group receiving pruritic substance administration and laser irradiation to the cervical spine, the group receiving pruritic substance administration and laser irradiation to the pruritic substance administration site, and the group receiving pruritic substance administration and laser irradiation to both the cervical spine and the pruritic substance administration site, compared to the group receiving pruritic substance administration and sham irradiation. There was no difference in the effectiveness of phototherapy depending on the irradiation site. Laser irradiation to the cervical spine can treat itching over a wide area of ​​skin and other regions innervated by sensory nerves connected to the spinal cord within the cervical spine, whereas laser irradiation to the site of pruritic substance administration can treat itching only at the site of administration, i.e., only the itching in the affected area. Therefore, light irradiation to sensory nerves is considered superior in that it can treat a wider area.

[0063] [Example 4] Comparative study of therapeutic and preventive effects on pruritus due to differences in irradiation intensity To compare the therapeutic and preventive effects on pruritus based on differences in average light power and irradiation time, groups were established using combinations of multiple average powers and irradiation times. As a test pruritus model, an acute pruritus test was conducted using pruritic substances widely used in non-clinical trials of pruritus.

[0064] The test procedure is as follows: [Model animals used] We conducted experiments to induce itching by intradermally administering pruritic substances to the backs of mice. Male mice, ICR, and 6-9 weeks old were used. The groups were divided into a pruritic substance administration / sham irradiation group and a pruritic substance administration / laser irradiation group. In the laser irradiation group, experimental condition 1 or experimental condition 2 below was used. Experimental conditions 1: Average power was 1, 10, 20, 30, and 100 mW; irradiation time was 180 seconds; the number of animals in each group was 8; the pruritic substances were histamine (His) (200 nmol / site, 50 μL), chloroquine (CQ) (200 μg / site, 50 μL), and serotonin (5-HT) (100 nmol / site, 50 μL). Experimental conditions 2: Average power was 30, 60, 100, and 150 mW, and the irradiation time at each average power was 30, 90, 180, 300, and 600 seconds; the number of animals in each group was 3; the pruritic substance was histamine (His) (200 nmol / site, 50 μL). The dummy irradiation group was a group in which no laser was emitted, and only experimental procedures equivalent to laser irradiation were performed. [Laser irradiation] Laser light was irradiated percutaneously to the cervical vertebrae of mice under the following irradiation conditions. The average power and irradiation time are shown in Figures 6A and 6B, and the peak power is 10 times the average power. Wavelength: 808 nm, pulsed oscillation, pulse width 20 ms, pulse pause time 180 ms, frequency: 5 Hz, duty cycle: 10%, irradiation area: 0.785 cm² 2 Laser irradiation was performed under isoflurane inhalation anesthesia. Isoflurane inhalation anesthesia was administered for 600 seconds in all groups. [Evaluation Method] The effectiveness of the treatment for pruritus was evaluated by measuring the number of times mice scratched. [Experimental Techniques] (1) The cervical spine of mice under isoflurane inhalation anesthesia was irradiated with a laser. The sham irradiation group received sham irradiation. (2) After releasing the patient from anesthesia, an itch-inducing substance was administered intradermally to the back two hours after laser irradiation or sham irradiation. (3) The number of scratching movements was measured for 30 minutes. [result] When laser irradiation was performed using experimental condition 1, the number of scratching movements was suppressed as the average power increased for all pruritic substances. In other words, it was found that the greater the average power, the greater the therapeutic and preventive effect against pruritus (Figures 7A-7C). Furthermore, when laser irradiation was performed using experimental condition 2, the number of scratching movements was suppressed as the average power and irradiation time increased for all pruritic substances. In other words, it was found that the greater the average power and the longer the irradiation time, the greater the therapeutic and preventive effect against itching. The product of average power and irradiation time is energy, and it can be said that the greater the energy, the greater the therapeutic and preventive effect (Figure 8). Moreover, it was found that at all average power levels, the therapeutic and preventive effect against itching in the pruritic substance administration / laser irradiation group was greater than that in the pruritic substance administration / sham irradiation group. In other words, it was found that a higher effect could be obtained even at low energy levels compared to the therapeutic and preventive effect in the sham irradiation group.

[0065] Based on these results, irradiation conditions for the human median nerve, human sciatic nerve, and human sacral nerve were calculated from the irradiation conditions in the mouse experiment (Tables 2-13). For example, in Table 2, an average power of 30 mW in mice corresponds to 9.7 mW in the human median nerve in terms of [mean depth - standard deviation] (mean depth is 4.9 mm (Table 1)) and 12.7 mW in terms of [mean depth + standard deviation]. Therefore, an average power of 30 mW in mice corresponds to 9.7-12.7 mW in the human median nerve.

[0066] [Table 2]

[0067] [Table 3]

[0068] [Table 4]

[0069] [Table 5]

[0070] [Table 6]

[0071] [Table 7]

[0072] [Table 8]

[0073] [Table 9]

[0074] [Table 10]

[0075] [Table 11]

[0076] [Table 12]

[0077] [Table 13]

[0078] Based on the above results, for irradiation of the human median nerve, the preferred irradiation conditions are an average power of 9.7 mW to 63.4 mW of light emitted from the light irradiation probe, and an average power density of 12 mW / cm² (average power divided by the irradiation area of ​​the light beam). 2 ~81mW / cm 2 The energy, which is the amount of light, is 0.3 J to 38 J per irradiation, and the energy density, which is the energy divided by the irradiation area of ​​the light, is 0.4 J / cm² per irradiation. 2 ~49J / cm 2It was found that the wavelength was 808 nm.

[0079] Furthermore, for irradiation of the human sciatic nerve, preferred irradiation conditions are an average power of 151 mW to 6110 mW of light emitted from the light irradiation probe, and an average power density of 192 mW / cm² (average power divided by the irradiation area of ​​the light beam). 2 ~7784 mW / cm² 2 The energy, which is the amount of light, is 4.5 J to 3666 J per irradiation, and the energy density, which is the energy divided by the irradiation area of ​​the light, is 5.8 J / cm² per irradiation. 2 ~4670 J / cm 2 It was found that the wavelength was 808 nm.

[0080] Furthermore, in the case of irradiation to the human sacral nerve, preferred irradiation conditions are an average power of 343 mW to 39998 mW of light emitted from the light irradiation probe, and an average power density of 437 mW / cm² obtained by dividing the average power by the irradiation area of ​​the light beam. 2 ~50953mW / cm 2 The energy, which is the amount of light, is 10.3 J to 23999 J per irradiation, and the energy density, which is the energy divided by the irradiation area of ​​the light, is 13.1 J / cm² per irradiation. 2 ~30572J / cm 2 It was found that the wavelength was 808 nm. [Industrial applicability]

[0081] As a new treatment method for itching, we have confirmed the effectiveness of phototherapy in suppressing itching, and we can offer a new physical therapy method. [Explanation of symbols]

[0082] 1. Itch treatment device 2. Light irradiation probe 3 ray source 4 Probe Cables 5 Main unit 6. Light source and power supply

Claims

1. A pruritic treatment device comprising a light source that emits light rays and a light irradiation probe that irradiates said light rays, characterized in that the light rays emitted from the light source are transcutaneously irradiated from the light irradiation probe toward sensory nerves that innervate the itchy area of ​​the skin or mucosal epithelium, wherein the average power of the light rays irradiated from the light irradiation probe is 32 mW to 26665 mW, the average power density obtained by dividing the average power by the irradiation area of ​​the light rays is 14 mW / cm² to 11748 mW / cm², the energy, which is the amount of light rays, is 5.8 J to 4800 J per irradiation, the energy density obtained by dividing the energy by the irradiation area of ​​the light rays is 2.6 J / cm² to 2115 J / cm² per irradiation, and / or the wavelength is 750 nm to 850 nm.

2. A pruritic treatment device comprising a light source that emits light rays and a light irradiation probe that irradiates the light rays, characterized in that the light rays emitted by the light source are transcutaneously irradiated from the light irradiation probe toward sensory nerves that innervate the itchy area of ​​the skin or mucosal epithelium, wherein the sensory nerves irradiated by the light rays are median nerves, sacral nerves, or sciatic nerves.

3. The itching treatment device according to claim 1 or 2, characterized in that the light source is built into the light irradiation probe and the device is portable.

Images