freckling

Freckling refers to small, flat pigmented spots on the skin that are usually tan to brown in color. Freckles are most commonly seen on sun-exposed areas such as the face, shoulders, and arms, and they tend to be more noticeable in people with fair skin and light hair. They are typically round to oval and measure a few millimeters in diameter.

Causes and characteristics: Freckles result from localized increases in melanin production in response to ultraviolet light. They often appear in childhood and may become more pronounced with sun exposure. Genetically, freckles are associated with variants in the MC1R gene, and their appearance is influenced by skin type and sun exposure. Freckles differ from moles in that they do not involve an increased number of melanocytes and are usually benign.

Types: Ephelides are the classic freckles that darken with sun exposure and fade in winter. Lentigines are longer-lasting, pigmented spots often linked to aging and cumulative sun exposure; they are sometimes called sun or age spots. Distinguishing between freckles, lentigines, and melanocytic nevi (moles) can be important for skin health monitoring.

Special cases: In neurofibromatosis type 1, freckling can occur in unusual locations such as the axillae (underarms) or groin and is a diagnostic feature of the condition, sometimes called axillary freckling or Crowe sign.

Management and prevention: Freckles are benign and often require no treatment. Protective sun practices are encouraged, including broad-spectrum sunscreen, protective clothing, and shade. Cosmetic options such as laser or light-based therapies exist but are elective. Any noticeable change in a freckle should be evaluated by a clinician.