Pigmentation

Pigmentation describes any area where the skin appears darker or more uneven in colour than the surrounding tissue. The umbrella term covers several distinct conditions with different causes, all of which involve excess melanin produced by the melanocytes in the basal layer of the epidermis or deposited in the dermis below. The most common presentations are sun-induced freckles (ephelides) and lentigines (age spots or sun spots), post-inflammatory hyperpigmentation (PIH) left behind after acne, eczema or another inflammatory insult, and melasma, a hormonally-driven pattern of darker patches across the cheeks, forehead, upper lip and jawline that is particularly common in women of childbearing age and in deeper phototypes. The mechanisms differ. Sunspots and freckles form when ultraviolet radiation triggers melanocytes to produce more melanin in localised patches, gradually deepening and expanding over years. Post-inflammatory hyperpigmentation reflects melanocyte overactivity in response to skin injury; darker phototypes are at much higher risk because their melanocytes are more reactive. Melasma is driven by hormonal signals (pregnancy, the combined contraceptive pill, hormonal contraception generally) and is worsened by heat, visible light and UV; its boundaries are often indistinct and the condition is notoriously stubborn. Other forms of dyspigmentation, including cafe-au-lait macules, Becker's nevi and drug-induced pigmentation, require dermatology input before aesthetic treatment. Treatment depends heavily on the pigment type, its depth (epidermal, dermal or mixed) and the patient's skin phototype. IPL (intense pulsed light) targets superficial epidermal pigmentation and is particularly effective for solar lentigines on the face, chest and hands in lighter phototypes, but can worsen melasma and is higher risk in deeper phototypes where the surrounding skin absorbs light as well. Chemical peels, from superficial glycolic or salicylic acid peels through to medium-depth TCA or Jessner's peels, remove pigmented superficial layers and encourage even re-pigmentation, and are often a safer first-line choice in darker phototypes. Laser resurfacing with fractional lasers can address deeper dermal pigmentation, with careful patient selection and staged protocols to minimise the risk of post-inflammatory hyperpigmentation as a paradoxical side effect. Home care is essential. Daily broad-spectrum SPF of at least 50, ideally with iron oxides to block visible light in melasma, prevents new pigment formation and is the single most important factor in maintaining treatment results. Tyrosinase-inhibiting topicals (hydroquinone, azelaic acid, kojic acid, tranexamic acid, cysteamine) reduce melanin production between clinic sessions.