Follicular Dowling-Degos Disease Camouflaged as Comedones: A Case Report and Literature Review

Abstract

Dowling-Degos disease (DDD) is an uncommon autosomal dominant genodermatosis that resides in the spectrum of diseases presenting with reticulate pigmentation. This disease has varied phenotypic expressions, the classical presentation being reticular pigmentation of flexures involving the axilla, submammary folds, inguinal folds, and neck. Follicular DDD is a variant of DDD with a unique presentation of folliculocentric papules, macules, pits, and comedones associated with the characteristic histological findings of follicle-centered, pigmented, branching, antler horn-like rete ridges sparing the interfollicular epidermis. Due to the rarity and paucity of data about this entity, we describe this case of a 28-year-old female who presented with perioral pitted scars and multiple hyperpigmented folliculocentric comedo-like papules over the face, neck, cubital fossa, and upper trunk, unaccompanied by the typical non-follicular, reticulate flexural hyperpigmentation, which clinically posed a diagnostic challenge. The diagnosis was confirmed by histopathology. We intend to increase clinicians’ cognizance with respect to the unique clinical and histopathologic presentation of follicular DDD. More genetic studies could bring more understanding of this complex spectrum.

Inherited Reticulate Pigmentary Disorders

“…DDD has been reported in different regions but is more common in Caucasians [ 35 , 42 ]. Follicular DDD, a distinct type of DDD, presents uniquely with characteristics such as hyperkeratotic follicular papules resembling comedones; acne-like scars with a pitted appearance around the mouth; and perianal reticulated pigmented lesions, which can be observed during adulthood [ 43 ]. Galli–Galli disease (GGD) is regarded as an acantholytic variant of Dowling-Degos [ 44 ].…”