Coexistence of reticulate acropigmentation of Kitamura and Dowling-Degos disease.

Reticulate acropigmentation of Kitamura (RAK) and Dowling-Degos Disease (DDD) are rare genodermatosis inherited as an autosomal dominant trait with variable penetrance. They are part of a spectrum of diseases with hyperpigmented macules coalescing in a reticular pattern, facial and palmoplantar pits, breaks in dermatoglyphics, comedo-like lesions and epidermoid cysts, and a unique histological picture of hyperpigmented digitate epidermal downgrowths. The authors describe the case of a 45-year-old female with reticulate acropigmentation of the dorsa of the hands and feet, hyperpigmented macules on the axilla and around the mouth, and palmar pitting. Clinical and histological findings, together with a relevant family history, allowed the authors to consider this case an example of the rare event of an overlap RAK-DDD.