Published on 18/03/2015 by admin
Filed under Dermatology
Last modified 18/03/2015
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Stephanie Ogden and Christopher E.M. Griffiths
Evidence Levels: A Double-blind study B Clinical trial ≥ 20 subjects C Clinical trial < 20 subjects D Series ≥ 5 subjects E Anecdotal case reports
Melasma is an acquired hypermelanosis that most commonly affects females of childbearing age, although males may also be affected. The condition can be classified according to the pattern of facial involvement which includes: centrofacial (forehead, cheeks, chin, and upper lip); malar; and mandibular. Less frequently the neck and forearms may be affected. Melasma is more prevalent in individuals with Fitzpatrick skin types III and above.
Three histological subtypes of melasma exist which may be differentiated by the use of a Wood’s lamp: epidermal melasma (enhanced contrast with Wood’s lamp), dermal melasma (less contrast), and mixed. Histological features of melasma include increased epidermal and dermal melanin, solar elastosis, damage to the basement membrane, increased vascularity, and increased numbers of dermal mast cells. Epidermal melasma is the most responsive to treatment.
The pathogenesis of melasma is not fully understood; however, hormonal factors, in particular pregnancy and the use of oral contraceptives, are the most common precipitants. Exposure to ultraviolet (UV) radiation both precipitates and exacerbates. Other etiological factors include phototoxic medications, genetic predisposition, and thyroid disease.
Melasma is often difficult to treat due to the recalcitrant and recurrent nature of the condition, and the risk of post-inflammatory hyperpigmentation associated with some treatments, particularly in individuals with darker skin. Pregnancy induced melasma may resolve spontaneously postpartum, and females taking the oral contraceptive pill may be advised to change to an alternative form of contraception.
Sun exposure increases melanin production and may exacerbate melasma; therefore all patients should receive sun protection advice and use a high factor broad spectrum sunscreen with good protection against UVA. Patients may also wish to use camouflage make-up.
Current treatment options include topical depigmenting agents, chemical peels and laser therapies. The response to monotherapy is often limited and therefore a combination of treatments may optimize outcome. Commonly used treatments include 2–5% hydroquinone, tretinoin, triple combination creams (containing hydroquinone, tretinoin, and fluocinolone), and azelaic acid. Glycolic acid is the most commonly reported peeling agent and may be used as an adjunct to topical depigmenting agents. The results of laser therapies are mixed and treatment carries a significant risk of relapse and post-inflammatory hyperpigmentation depending on the type of laser used. Currently only the fractional resurfacing laser has FDA approval for the treatment of melasma.
Thyroid function tests
Lufti RJ, Fridmanis M, Misiunas AL, Pafume O, Gonzalez EA, Villemur JA, et al. J Clin Endocrinol Metab 1985; 61: 28–31.
The prevalence of thyroid abnormalities in 84 non-pregnant females with melasma was significantly higher than in age- and sex-matched controls (58% compared with 12%).
Sheth VM, Pandya AG. J Am Acad Dermatol 2011; 65: 699–714.
Topical treatment with triple combination cream and sunscreen was the recommended first-line treatment. Recommendation that chemical peels should be used in combination with topical depigmenting agents to reduce the risk of post-inflammatory hyperpigmentation.
Rajaratnam R, Halpern J, Salim A, Emmett C. Cochrane Database Syst Rev 2010; CD003583.
This Cochrane review was unable to recommend a standard therapy for melasma due to the heterogeneity, poor quality, or inadequate follow-up in the 20 studies reviewed.
Taylor SC, Torok H, Jones T. Cutis 2003; 72: 67–72.
Two multicenter, randomized studies compared the efficacy and safety of a formulation containing tretinoin 0.05%, hydroquinone 4%, and fluocinolone acetonide 0.01% with the three possible dual combinations of the three agents in 641 patients with melasma (Fitzpatrick skin types I–IV). The triple combination formulation was significantly more effective than any of the dual combinations. At week 8 a 75% reduction in melasma/pigmentation was observed in more than 70% of patients treated, compared to 30% in patients using dual therapy.
Treatment of Skin Disease Comprehensive Therapeutic Strategies 4e
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Triple combination cream
Hydroquinone
Tretinoin
Adapalene
Sunscreen
