Acute febrile neutrophilic dermatosis. A histopathological study of 37 patients and a review of the literature.

More than 100 cases of acute febrile neutrophilic dermatosis (AFND) have been documented since the original description by Sweet in 1964. Review articles have focused on clinical features. The present study documents the histopathological features of 54 biopsies obtained from 37 patients with early AFND. All patients fulfilled the criteria for the diagnosis of AFND as suggested by Su and Liu. Macular, papulonodular and scaly, annular, or arciform lesions are represented, histopathologically by lymphocytic, predominantly neutrophilic, and mixed infiltrates with a prominent histiocytic component. Characteristic histopathology--i.e., a pale, edematous epidermis, subepidermal edema with extravasated red cells, and a more or less diffuse infiltrate of mature neutrophilis in the upper dermis without vasculitis--is only found during the neutrophilic phase. This is an important consideration when evaluating sections of patients with possible AFND. AFND is a disease that represents a wide spectrum of clinical and histological features. Implications regarding differential diagnoses are discussed.