Freckle

Freckle is a common, flat, pigmented spot on the skin that arises from localized melanin production rather than an increase in the number of pigment-producing cells. Freckles are usually small, about 1–2 mm in diameter, and appear tan or light brown. They are most noticeable in sun-exposed areas such as the face, shoulders, and arms, and are more common in people with lighter skin (Fitzpatrick type I–II).

Causes and genetics: Freckles develop when melanocytes produce more melanin in response to ultraviolet radiation. The propensity to form freckles is influenced by genetics, with variants of the MC1R gene associated with freckles and red hair. Freckles typically appear in childhood or adolescence and become more pronounced with sun exposure; they often fade in winter.

Differentiation from other nevi: Freckles, or ephelides, differ from lentigines (solar lentigines or age spots) in that freckles reflect increased melanin production in each cell and tend to fade when sun exposure decreases, whereas lentigines involve an increased number of melanocytes and persist with age.

Management and monitoring: Freckles themselves are harmless. Protective measures such as sunscreen, hats, and protective clothing help prevent darkening. For cosmetic reasons, some people pursue topical depigmenting agents, retinoids, or laser therapy, though results vary and safety should be discussed with a clinician. If a new spot appears in adulthood or a freckle changes in size, shape, color, or border, seek medical evaluation to rule out skin cancer.