Synopsis
Distinguish patterned melasma from pigment left by inflammation, identify atypical or iatrogenic causes, and use slow, low-irritancy treatment that does not intensify dyschromia.
- Melasma causes acquired symmetrical brown or grey-brown facial patches, commonly centrofacial or malar, influenced by ultraviolet and visible light, hormones and genetic susceptibility.
- Post-inflammatory hyperpigmentation follows eczema, acne, infection, trauma, procedures or irritation and mirrors the sites and shapes of the preceding inflammatory process.
- Both are more visible and often more persistent in richly pigmented skin; this reflects melanin biology and treatment response, not poor hygiene or inadequate care.
Key red flags
A single changing irregular pigmented lesion, mucosal or nail pigmentation, bleeding, ulceration, palpable infiltration, systemic illness or rapid unexplained diffuse pigmentation requires prompt diagnostic assessment rather than empirical lightening treatment.
Investigation priorities
Separate patterned melasma, inflammatory pigment and an exposure-related reaction.
Management branches
Facial or localised hyperpigmentation is the presenting concern.
- Map distribution and colour, examine surface and compare current pigment with photographs and the shape of any preceding inflammatory eruption.
- Review pregnancy, hormonal contraception, systemic and topical medicines, cosmetics, peels, friction and occupational light or chemical exposure.
Key medicines
Azelaic acid 20% creamApply a thin layer to affected facial skin twice daily after gentle cleansing; reduce to once daily or pause briefly if irritation is troublesome.
Hydroquinone specialist pigment treatmentUse only the dermatologist-selected unlicensed or compounded concentration, often once nightly for a strictly time-limited course with a documented stop date.