WordNet

a tan discoloration of a womans face that is associated with pregnancy or with the use of oral contraceptives (同)melasma, mask of pregnancy
dry (ink) with blotting paper
an act that brings discredit to the person who does it; "he made a huge blot on his copybook" (同)smear, smirch, spot, stain

PrepTutorEJDIC

(特に,インクなどの)汚れ,しみ / (人格・名声などにつけられた)汚点,汚名 / 〈他〉…‘に'しみおつける,'を'汚す / (吸取紙で)…‘の'汚れ(しみ)を吸い取る;〈汚れ・しみ〉'を'吸い取る
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）』「2015/06/14 22:11:39」(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.

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. Melasma is also common in pre-menopausal women. It is thought to be enhanced by surges in certain hormones.

Cause

Melasma is thought to be the stimulation of melanocytes (cells in the epidermal layer of skin that produce a pigment called melanin) 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.^[3] 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
Hydroquinone-induced exogenous ochronosis (see Ochronosis#Treatment_of_Exogenous_Ochronosis)

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. Assessment by a dermatologist will help guide treatment. This may include use of a Woods lamp to determine depth of the melasma pigment. 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 aesthetician's office or as a home massager unit.
Laser and IPL
Oral Tranexamic acid has shown to provide rapid and sustained lightening in melasma by decreasing melanogenesis in epidermal melanocytes.

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.

Patients should avoid other precipitants including hormonal triggers.

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.
^ Lutfi, R. J.; Fridmanis, M; Misiunas, A. L.; Pafume, O; Gonzalez, E. A.; Villemur, J. A.; Mazzini, M. A.; Niepomniszcze, H (1985). "Association of melasma with thyroid autoimmunity and other thyroidal abnormalities and their relationship to the origin of the melasma". The Journal of clinical endocrinology and metabolism 61 (1): 28–31. doi:10.1210/jcem-61-1-28. PMID 3923030. edit

External links

DermNet colour/melasma

UpToDate Contents

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1. 肝斑 melasma
2. 色素沈着過剰を有する患者へのアプローチ approach to the patient with hyperpigmentation disorders
3. 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
4. 妊娠中の肌、髪、爪、粘膜 the skin hair nails and mucous membranes during pregnancy
5. 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

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 DB1, Suh HS, Choi YS.
The Journal of dermatological treatment.J Dermatolog Treat.2014 Dec;25(6):523-8. doi: 10.3109/09546634.2013.848261. Epub 2013 Dec 2.
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
PMID 24289244

In vivo study of spoilage bacteria on polyphenoloxidase activity and melanosis of modified atmosphere packaged Pacific white shrimp.

Qian YF1, Xie J2, Yang SP1, Wu WH1, Xiong Q1, Gao ZL1.
Food chemistry.Food Chem.2014 Jul 15;155:126-31. doi: 10.1016/j.foodchem.2014.01.031. Epub 2014 Jan 23.
This study investigated the effect of the three spoilage bacteria (Carnobacterium maltaromaticum, Shewanella putrefaciens and Aeromonas salmonicida) on the development of melanosis by inoculating the bacteria on modified atmosphere packaged shrimp. The three bacteria, which inoculated at about 5 log
PMID 24594164

A giant congenital melanocytic nevus associated with neurocutaneous melanosis.

Kim SJ1, Kim JH, Son B, Yoo C.
Clinical neuroradiology.Clin Neuroradiol.2014 Jun;24(2):177-84. doi: 10.1007/s00062-013-0217-y. Epub 2013 Oct 31.
PMID 24173435

Japanese Journal

Grevillosides J–Q, Arbutin Derivatives from the Leaves of Grevillea robusta and Their Melanogenesis Inhibitory Activity

, , , ,
Chemical and Pharmaceutical Bulletin 62(4), 364-372, 2014
… For exploitation as skin-lightening and anti-chloasma agents, the inhibitory activities of the isolated compounds as well as ones isolated in previous experiments (19–31) toward tyrosinase and melanin-producing B16 cells were assayed. …
NAID 130003390786

von Recklinghausen 病に肺腺癌, 胸壁脂肪腫を合併した一例

道免寛充,岩代望,中西喜嗣,小室一輝,石坂昌則
日本呼吸器外科学会雑誌 = The journal of the Japanese Association for Chest Surgery 24(6), 940-944, 2010-09-15
症例は71歳男性．幼少時より皮膚多発結節および褐色斑がみられ，von Recklinghausen病と診断されていた．6年前から自覚していた緩徐な増大傾向を示す右側胸部腫瘤の経過観察中にCT検査で右肺に2cm大のすりガラス状陰影を指摘された．2009年3月のCT検査で同陰影の増大傾向および陰影内部の濃度上昇を認め肺腺癌が疑われ当科紹介となった．まず胸壁腫瘍を全身麻酔下に摘出した．病理組織学的に脂肪 …
NAID 10026639672