Alopecic and Aseptic Nodules of the Scalp: A New Entity or a Minor Form of Dissecting Cellulitis?

Since the original report in 1992 and revised nomenclature in 2009, pseudocysts of the scalp and alopecic and aseptic nodules of the scalp (AANS), respectively, have been regarded as a new entity that is rare and not understood in its pathogenesis. We observed 26 cases of AANS. Except for the extent and severity of disease, we found no single feature that justifies distinguishing AANS as a nosologic entity in its own right from dissecting cellulitis of the scalp (DCS). The scarring alopecias represent a diverse group of disorders with the potential of permanent destruction of the pilosebaceous unit and hair loss. Within the maze of varied conditions leading to scarring alopecia, the most important is to keep a neat nosologic classification in mind, based both on morphology and a pathogenic understanding. We believe that AANS represents a minor form of DCS, so far predominantly observed in patients of non-African origin, and therefore, is a disease of follicular occlusion with a favorable prognosis.