Dowling-Degos disease, hidradenitis suppurativa, and multiple keratoacanthomas. A disorder that may be caused by a single underlying defect in pilosebaceous epithelial proliferation.

We report a case in which one patient had Dowling-Degos disease (reticulate pigmented anomaly of the flexures), hidradenitis suppurativa, and multiple keratoacanthomas. Abnormal epithelial proliferation involving mainly the pilosebaceous apparatus has been recognized in all three conditions. We speculate that a single underlying defect in follicular epithelial proliferation, characterized by variable expressivity, accounts for the coexistence of these clinically distinct disorders of follicular derivation.