Reticular pigmented anomaly of the flexures.

Reticular pigmented anomaly of the flexures (Dowling-Degos' anomaly) is a rare, benign, new genodermatosis that has recently evolved from independent observations and studies by several dermatologists. Because of its favorable prognosis, differentiation of this benign disorder from acanthosis nigricans, a cutaneous marker of possible or existing internal malignant disease, is highly important. Careful clinical appraisal of the eruption in correlation with the characteristic microscopic features makes the diagnosis simple and straightforward.