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黒色症(皮膚や髪に多量の黒い色素の出る病気)

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2012/10/24 16:13:29」(JST)

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Melasma (also known as Chloasma faciei,^[1]^:854 or the mask of pregnancy^[2] when present in pregnant women) is a tan or dark skin discoloration. Although it can affect anyone, melasma is particularly common in women, especially pregnant women and those who are taking oral or patch contraceptives or hormone replacement therapy (HRT) medications. It is also prevalent in men and women of Native American descent (on the forearms) and in men and women of German, Russian, and Jewish descent (on the face).^{[citation needed]}

Symptoms

The symptoms of melasma are dark, irregular well demarcated hyperpigmented macules to patches commonly found on the upper cheek, nose, lips, upper lip, and forehead. These patches often develop gradually over time. Melasma does not cause any other symptoms beyond the cosmetic discoloration.

Cause

Melasma is thought to be the stimulation of melanocytes or pigment-producing cells by the female sex hormones estrogen and progesterone to produce more melanin pigments when the skin is exposed to sun. Women with a light brown skin type who are living in regions with intense sun exposure are particularly susceptible to developing this condition.

Genetic predisposition is also a major factor in determining whether someone will develop melasma.

The incidence of melasma also increases in patients with thyroid disease. It is thought that the overproduction of melanocyte-stimulating hormone (MSH) brought on by stress can cause outbreaks of this condition. Other rare causes of melasma include allergic reaction to medications and cosmetics.

Melasma Suprarenale (Latin - above the kidneys) is a symptom of Addison's disease, particularly when caused by pressure or minor injury to the skin, as discovered by Dr. FJJ Schmidt of Rotterdam in 1859.

Differential diagnosis

Post inflammatory hyperpigmentation
Actinic lichen planus

Diagnosis

Melasma is usually diagnosed visually or with assistance of a Wood's lamp (340 - 400 nm wavelength). Under Wood's lamp, excess melanin in the epidermis can be distinguished from that of the dermis.

Treatment

The discoloration usually disappears spontaneously over a period of several months after giving birth or stopping the oral contraceptives or hormone replacement therapy.

Treatments are often ineffective as it comes back with continued exposure to the sun. Treatments to hasten the fading of the discolored patches include:

Topical depigmenting agents, such as hydroquinone (HQ) either in over-the-counter (2%) or prescription (4%) strength. HQ is a chemical that inhibits tyrosinase, an enzyme involved in the production of melanin.
Tretinoin, an acid that increases skin cell (keratinocyte) turnover. This treatment cannot be used during pregnancy.
Azelaic acid (20%), thought to decrease the activity of melanocytes.
Chemical peels.
Microdermabrasion to dermabrasion (light to deep).
Galvanic or ultrasound facials with a combination of a topical crème/gel. Either in an æsthetician's office or as a home massager unit.
Laser treatment. A Wood's lamp test should be used to determine whether the melasma is epidermal or dermal. Dermal melasma often proves difficult to treat, and has only been found to lighten with products containing mandelic acid (such as Triluma cream) Profractional (Sciton) or Fraxel laser or laser phototherapy (Intense pulsed light ).^[3]

In all of these treatments the effects are gradual and a strict avoidance of sunlight is required. The use of broad-spectrum sunscreens with physical blockers, such as titanium dioxide and zinc dioxide is preferred over that with only chemical blockers. This is because UV-A, UV-B and visible lights are all capable of stimulating pigment production.

Cosmetic camouflage can also be used to hide melasma.

References

^ James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN 0-7216-2921-0.
^ Tunzi M, Gray GR (January 2007). "Common skin conditions during pregnancy". Am Fam Physician 75 (2): 211–8. PMID 17263216.
^ G Zoccali, D Piccolo, P Allegra, M Giuliani (March 2010). "Melasma Treated with Intense Pulsed Light". Aesthetic Plastic Surgery 34 (4): 486–93. doi:10.1007/s00266-010-9485-y. PMID 20225000. http://www.springerlink.com/content/g716u77711px22x0/.

External links

Melasma Treatment Options - Melasma Treatment
DermNet colour/melasma
Health In Plain English - Melasma or Chloasma
MSM for Melasma - Megadoses of sulphur helps some sufferers

UpToDate Contents

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1. 肝斑 melasma
2. 斑状の皮膚病変を有する患者へのアプローチ approach to the patient with macular skin lesions
3. 妊娠中の肌、髪、爪、粘膜 the skin hair nails and mucous membranes during pregnancy
4. 皮膚色素過剰症に対するレーザーおよび光線療法 laser and light therapy for cutaneous hyperpigmentation
5. アンドロゲン過剰症および男性型多毛症治療におけるエストロゲン・プロゲスチン
混合避妊剤の使用 use of combination estrogen progestin contraceptives in the treatment of hyperandrogenism and hirsutism

English Journal

A comparative study of low-fluence 1064-nm Q-switched Nd:YAG laser with or without chemical peeling using Jessner's solution in melasma patients.

Lee DB, Suh HS, Choi YS.Author information Department of Dermatology, Ulsan University Hospital , Ulsan , Korea.AbstractAbstract Background: Although low-fluence 1064-nm Q-switched Nd:YAG laser (QSNYL) is widely used for the treatment of melasma, multiple treatments are necessary for clinical improvement. Superficial chemical peeling using Jessner's solution has been used for treatment of melasma conventionally. Objectives: To evaluate the additional therapeutic effect and adverse effects of Jessner's peel when combined with 1064-nm QSNYL for melasma patients in a double-blind, placebo-controlled design. Methods: Total of 52 patients were included. Patients who received 10 sessions of 1064-nm QSNYL plus chemical peeling with placebo (group A) in a two-week interval and those who received 10 sessions of 1064-nm QSNYL plus chemical peeling with Jessner's solution (group B) in a two-week interval were analyzed. Responses were evaluated using the Melasma Area and Severity Index (MASI) score, physician's global assessment (PGA) and subjective self-assessment. Results: At 8 weeks, the mean MASI score decreased from 8.68 ± 4.06 to 8.60 ± 3.88 in group A and from 8.98 ± 3.72 to 7.13 ± 2.57 in group B, showing a significant difference (p < 0.001). But at 20 weeks, there was no significant difference on reduction of MASI, self-assessment and PGA between the two groups. No serious adverse effects were reported with the additional Jessner's peeling. Conclusion: This study suggests Jessner's peel is a safe and effective method in the early course of treatment for melasma when combined with low-fluence 1064-nm Q-switched Nd:YAG laser.
The Journal of dermatological treatment.J Dermatolog Treat.2014 Dec;25(6):523-8. doi: 10.3109/09546634.2013.848261. Epub 2013 Dec 2.
Abstract Background: Although low-fluence 1064-nm Q-switched Nd:YAG laser (QSNYL) is widely used for the treatment of melasma, multiple treatments are necessary for clinical improvement. Superficial chemical peeling using Jessner's solution has been used for treatment of melasma conventionally. Obje
PMID 24289244

Adverse events of non-ablative fractional laser photothermolysis: a retrospective study of 856 treatments in 362 patients.

Lee SM, Kim MS, Kim YJ, Won CH, Lee MW, Choi JH, Moon KC, Chang SE.Author information Department of Dermatology, Asan Medical Center, University of Ulsan College of Medicine, Pureen Skin Clinic , Seoul , Korea.AbstractBackground: Non-ablative fractional laser photothermolysis (NAFP) has been used effectively in the treatment of photodamaged skin and scars, with short post-operative recovery times; but, studies evaluating its adverse events and complication rates in Asian population have been limited. Objective: To determine the frequency and range of adverse events associated with NAFP treatment in Korean patients. Materials and methods: We retrospectively evaluated the outcomes of 754 1550-nm erbium-doped and 102 1927-nm thulium fiber fractional laser treatments in patients with skin phototypes III-IV treated at a single center. Adverse events were identified and tabulated, as were patient demographics and laser parameters. Results: From 856 treatments, there were 43 adverse events (5.0%), the most frequent being prolonged erythema (1.8%), post-inflammatory hyperpigmentation (1.1%) and aggravation of melasma (0.9%). Less frequently observed adverse events included herpes simplex outbreak (0.6%) and acneiform eruption (0.2%). There were no reports of long-term adverse events. Conclusion: Non-ablative fractional laser skin treatment has a relatively low complication rate. The adverse events found were temporary and did not result in long-term or severe sequelae such as hypertrophic scarring, atrophic scarring or permanent pigmentary alteration.
The Journal of dermatological treatment.J Dermatolog Treat.2014 Aug;25(4):304-7. doi: 10.3109/09546634.2013.777151. Epub 2013 Jul 11.
Background: Non-ablative fractional laser photothermolysis (NAFP) has been used effectively in the treatment of photodamaged skin and scars, with short post-operative recovery times; but, studies evaluating its adverse events and complication rates in Asian population have been limited. Objective: T
PMID 23639051

Treatment of melasma by low-fluence 1064 nm Q-switched Nd:YAG laser.

Sim JH, Park YL, Lee JS, Lee SY, Choi WB, Kim HJ, Lee JH.Author information Department of Dermatology, College of Medicine, Soonchunhyang University , Seoul , Korea.AbstractBackground: Low-fluence 1064 nm Q-switched Nd:YAG laser has recently been shown to be effective for the melasma treatment. Objective: The purpose of this study is to evaluate the clinical efficacy and safety of low-fluence 1064 nm Q-switched Nd:YAG laser treatment of melasma in Asian patients. Methods: Fifty patients with melasma underwent 15 weeks of weekly treatments, using a Q-switched Nd:YAG laser (RevLite®; HOYA ConBio®, Freemont, CA, USA) at 1064 nm with an 8-mm spot size, and a fluence of 2.8 J/cm(2). Patients and investigators subjectively evaluated the intensity of pigmentation after completion of 15 weekly treatments. The objective assessment was also performed with digital photographs and a pigment imaging tool (Janus®, PSI Co., Ltd., KOREA). Results: Both patients and investigators rated the treatment outcome as "good improvement" on average with improvement rate of 50-74%. The pigment imaging technology system also confirmed the improvement of the pigmentation level on all three locations of the face. None of the 50 patients showed any signs of severe side effects during the course of the treatment. Conclusion: Low-fluence 1064 nm Q-switched Nd:YAG laser is an effective method to treat melasma without serious side effects in Asian patients.
The Journal of dermatological treatment.J Dermatolog Treat.2014 Jun;25(3):212-7. doi: 10.3109/09546634.2012.735639. Epub 2013 Feb 24.
Background: Low-fluence 1064 nm Q-switched Nd:YAG laser has recently been shown to be effective for the melasma treatment. Objective: The purpose of this study is to evaluate the clinical efficacy and safety of low-fluence 1064 nm Q-switched Nd:YAG laser treatment of melasma in Asian patients. Metho
PMID 23030603