lentigines

Lentigines, commonly referred to as age spots or sun spots, are flat, small, well-defined pigmented macules that arise on sun-exposed skin. They result from localized epidermal hyperpigmentation, typically due to increased melanin in basal keratinocytes and, in some forms, a higher density of melanocytes. Lentigines are benign and distinct from freckles (ephelides) which darken with sun exposure but may fade without sun.

There are several types:

Solar lentigines are the most common in adults and appear on the face, hands, forearms, and other sun-exposed areas. They are strongly associated with cumulative ultraviolet exposure and aging. Lentigo simplex refers to solitary lesions that can occur at any age and are not specifically linked to UV exposure. More rarely, multiple lentigines occur as part of genetic syndromes such as Peutz-Jeghers syndrome (mucocutaneous lentigines with GI polyps) or LEOPARD syndrome (multiple lentigines with cardiac and other abnormalities). Neurofibromatosis type 1 may feature axillary or inguinal freckling that is sometimes called lentigines.

Diagnosis is clinical; dermoscopy can help distinguish lentigines from melanocytic nevi or melanoma. A biopsy is rarely needed unless the lesion changes or is atypical.

Management focuses on cosmetic considerations and sun protection. Treatments include cryotherapy, laser therapies (e.g., Q-switched, fractional lasers), chemical peels, or topical agents such as hydroquinone or retinoids, but lesions may recur with sun exposure. Preventive measures include regular sunscreen use and minimizing UV exposure.

Prognosis is excellent; solitary lentigines are benign. However, new or changing pigmented lesions should be evaluated for melanoma, and any lentigines associated with recognized syndromes require medical follow-up.