Melasma

Melasma is a common acquired disorder of hyperpigmentation presenting as symmetric, brown to grey brown patches on the face.

• Prevalence is 1 to 50% depending on population, predominantly in women (90%), of Fitzpatrick skin types III to VI, with onset between 20 and 40 years.
• Triggers: ultraviolet and visible light exposure, pregnancy, oral contraceptives and hormone replacement, thyroid disease, genetic predisposition, certain drugs (anticonvulsants, photosensitising drugs), and cosmetics.
• Pathogenesis: melanocyte hyperfunction, dermal fibroblast and vascular changes.
• Chronic, relapsing course, with recurrence in over 50% after treatment.

• Symmetric hyperpigmented macules and patches on the centrofacial (cheeks, forehead, nose, upper lip, chin), malar, or mandibular areas.
• Epidermal (brown, well defined, improves with Wood lamp enhancement), dermal (blue grey, no Wood lamp enhancement), or mixed types.
• Asymptomatic, though with major psychosocial impact.
• Extrafacial involvement (neck, forearms) is possible.

• Clinical, with Wood lamp and dermoscopy to determine depth.
• Severity: MASI (Melasma Area and Severity Index) or mMASI.
• Check TSH, and consider hormonal evaluation if menstrual irregularity or hirsutism.
• Biopsy only if atypical: increased melanin in epidermis and dermis, solar elastosis, and increased vascularity.
• Exclude post-inflammatory hyperpigmentation, Riehl melanosis, Hori naevus, drug induced pigmentation (minocycline, amiodarone), lentigines, and lupus.

• Sun and visible light protection is the foundation: broad spectrum SPF 50+ tinted with iron oxides applied daily and reapplied, wide brimmed hats, and avoidance of heat.
• Stop or modify aggravating hormones where possible.
• First line topical: triple combination cream (hydroquinone 4%, tretinoin 0.05%, fluocinolone acetonide 0.01%) nightly for 8 to 12 weeks, then maintain with a non-steroid regimen to avoid atrophy.
• Alternatives: hydroquinone 2 to 4% (limit to 3 to 6 months to avoid ochronosis), azelaic acid 15 to 20% twice daily, kojic acid 2 to 4%, cysteamine 5%, thiamidol, niacinamide 4 to 5%, tranexamic acid topical 3 to 5%, vitamin C serums.
• Oral tranexamic acid 250 mg twice daily (or 325 mg twice daily) for 3 to 6 months (screen for thrombosis risk; avoid in prior VTE, oestrogen use, or coagulopathy); also oral polypodium leucotomos 240 mg twice daily as photoprotection.
• Procedures: superficial chemical peels (glycolic acid 30 to 70%, salicylic acid 20 to 30%, TCA 10 to 15%) and low fluence Q-switched Nd:YAG laser as adjuncts; avoid aggressive lasers, IPL, and dermabrasion.
• Long term maintenance and expectation management.