Generalized dowling-degos disease: case reports.

Dowling-Degos disease (DDD) is a rare autosomal dominant trait characterized by numerous, symmetrical, progressive and pigmented macules over the axillae, groins, face, neck, arms and trunk as well as scattered comedo-like lesions (dark dot, follicles) and pitted acneiform scars. Histopathology is diagnostic testing using a distinctive form of acanthosis, characterized by an irregular elongation of thin branching rete ridges, with a concentration of melanin at the tips. We report cases of generalized DDD in a single family with autosomal dominant penetrance. DDD can be presented in a generalized form with hypopigmented lesions instead of reticulate hyperpigmentation confined to the flexor areas. This form can be differentiated from DUH by histopathology.