Melasma is an acquired hypermelanosis presenting as symmetric hyperpigmented macules and patches on sun-exposed facial skin (centrofacial, malar, mandibular patterns). It results from UV/visible light exposure interacting with genetic, hormonal, and vascular factors, with increased melanogenesis and dermal changes. Management requires multimodal therapy: photoprotection (including visible light), topical depigmenting agents (hydroquinone-based or alternatives), procedural therapies for select patients, and maintenance to prevent relapse.
Epidemiology
- More common in women and in Fitzpatrick skin types III–V; onset in reproductive years.
- Triggers: pregnancy (chloasma), oral contraceptives, hormone therapy, UV and visible light, heat.
Pathophysiology
- Increased melanogenic activity and melanosome transfer; epidermal, dermal, or mixed patterns.
- Upregulated melanogenesis pathways (MITF, tyrosinase), dermal changes (solar elastosis), mast cell proliferation, vascular component (VEGF).
- Visible light and heat can exacerbate via opsin and NO pathways; why broad-spectrum plus iron oxide-containing tinted sunscreens help.
Clinical Features
- Symmetric, ill-defined brown to gray-brown patches on forehead, cheeks, upper lip, chin; neck/forearms in some.
- Dermoscopic and Wood’s lamp can help assess depth but are not definitive.
Differential Diagnosis
- Postinflammatory hyperpigmentation, drug-induced hyperpigmentation (minocycline, amiodarone), lichen planus pigmentosus, exogenous ochronosis, acanthosis nigricans, Riehl melanosis, erythema dyschromicum perstans.
Management
- Photoprotection (cornerstone)
- Daily broad-spectrum SPF 50+ with high UVA and HEVL protection; use tinted sunscreens with iron oxides to block visible light.
- Sun-avoidance behaviors; hats; reapplication every 2–3 hours outdoors; heat mitigation.
- Topical depigmenting regimens
- Hydroquinone (HQ) 2–4% once daily cycles (e.g., 8–12 weeks) often in triple combination:
- Triple combination cream (TCC): HQ 4% + tretinoin 0.05% + fluocinolone 0.01% nightly for up to 8–12 weeks; effective for many.
- Non-HQ or maintenance options:
- Azelaic acid 15–20%, kojic acid, arbutin, tranexamic acid (topical), niacinamide, cysteamine 5% cream.
- Retinoids as adjuncts to enhance turnover and penetration.
- Avoid prolonged continuous HQ to minimize exogenous ochronosis risk—use cyclic or maintenance with non-HQ agents.
- Systemic agents
- Oral tranexamic acid (TXA) 250 mg bid for 3–6 months improves refractory melasma in many; assess thrombosis risk and contraindications (history of VTE, thrombophilia, OCP use caution); monitor for GI upset and rare adverse events; relapse can occur after stopping.
- Procedures (select patients, experienced hands)
- Chemical peels: superficial peels (glycolic 20–35%, salicylic 20–30%, lactic, Jessner) in series; risk of PIH especially in darker skin—pre-treat and practice conservative protocols.
- Lasers/light: low-fluence Q-switched or picosecond lasers, fractional non-ablative devices; higher relapse and PIH risk—reserve for refractory cases with strict maintenance and sun protection.
- Microneedling with topical lightening agents as adjunct in some.
- Maintenance and relapse prevention
- After clearance, continue strict photoprotection and maintenance topicals (azelaic acid, niacinamide, retinoids); intermittent short HQ cycles for relapses.
- Special scenarios
- Pregnancy: avoid HQ and retinoids; use azelaic acid and rigorous photoprotection.
- Skin of color: high PIH risk—favor non-irritating regimens; proceed cautiously with procedures; emphasize tinted sunscreens.
Prognosis
- Chronic and relapsing; significant improvement achievable with adherence.
- Relapse common with UV/visible light exposure or hormonal triggers; maintenance essential.
References (recent guidelines and key reviews)
- International melasma management consensus and algorithms, 2022–2024.
- RCTs and meta-analyses of TXA (topical and oral), TCC, and sunscreen strategies including iron oxide, 2021–2024.
- Reviews on vascular/dermal components and device-based therapies, 2022–2024.
- Safety reviews on hydroquinone use and exogenous ochronosis prevention, 2021–2024.