Neutrophilic eccrine hidradenitis: a retrospective study.

BACKGROUND: Neutrophilic eccrine hidradenitis (NEH) is a benign neutrophilic dermatosis not well recognized beyond an association with malignancy. Although the disease is commonly reported in adults with malignancy, this association is uncommon in children. The diagnosis of NEH is predominantly based on histologic findings to exclude alternative diagnoses for adults, but biopsy is not usually required for children.

METHODS: A retrospective study was performed of adult and pediatric patients diagnosed with NEH at three Mayo Clinic sites from January 1, 1992, to January 1, 2022. The aim of this study was to elucidate risk factors for NEH and its clinical characteristics, treatment options, and natural course. Clinical information and pathologic results were collected from health records. Available pathologic slides were reviewed with a dermatopathologist.

RESULTS: Of 47 patients identified, 33 had either histologic or clinical confirmation of the diagnosis; 21 were adults (64%), and 12 were children (36%). Most adults (16/21; 76%) had underlying malignancy and received chemotherapy. Five adults (24%) were classified as having idiopathic NEH, and they were younger and had higher NEH recurrence rates than the other adults. Only one pediatric patient (8%) had underlying malignancy. For 10 children (83%), NEH was preceded by strenuous activity. Initial findings of idiopathic NEH were palmoplantar eruptions for both adult and pediatric patients, whereas malignancy-associated NEH commonly involved the face and axillae.

CONCLUSIONS: Among adults, NEH is commonly associated with malignancy and chemotherapy. Among children, idiopathic NEH occurs primarily after overexertion, and malignancy is highly unlikely to be the cause of NEH.