Melasma



Melasma


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


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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.



Management strategy


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.




First-line therapies





















image Triple combination cream A
image Hydroquinone A
image Tretinoin A
image Adapalene A
image Sunscreen A









A randomized controlled trial of the efficacy and safety of a triple fixed combination (fluocinolone acetonide 0.01%, hydroquinone 4%, tretinoin 0.05%) compared with hydroquinone 4% cream in Asian patients with moderate to severe melasma.

Chan R, Park KC, Lee MH, Lee ES, Chang SE, Leow YH, et al. Br J Dermatol 2008; 159: 697–703.


Comparison of a triple combination cream (applied once daily) with 4% hydroquinone (applied twice daily) in 260 patients (majority skin phototype IV). The triple combination cream was significantly more effective: 64% of patients achieved a melasma global severity score of none or mild after 8 weeks, compared with 39% in the hydroquinone group. There were more adverse events in the triple combination group, but none were severe.


Commonly reported adverse effects include mild erythema, burning, and peeling.

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Aug 7, 2016 | Posted by in Dermatology | Comments Off on Melasma

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