Neutrophilic Dermatosis Limited to Lipo-Lymphedematous Skin in a Morbidly Obese Woman on Dasatinib Therapy

Neutrophilic dermatosis (ND) confined to postmastectomy lymphedema, localized Sweet syndrome, is a newly recognized disease. In this study, the authors describe a 44-year-old obese woman with chronic myelogenous leukemia in molecular remission on dasatinib therapy, who presented with a painful urticarial eruption limited to lipo-lymphedematous skin and accompanied by malaise, episodic fever, diarrhea, neutrophilia, and leukocytosis. Initially transient and migratory, the rash became fixed, papular, and vesicular and showed minimal response to corticosteroids. Biopsy demonstrated sparse perivascular and interstitial dermal neutrophilic infiltrates, without vasculitis or significant dermal edema. Aggregates of neutrophils were found within and surrounding lymphangiectases. Biopsy of a new onset papule 3 weeks later demonstrated papillary dermal edema, denser neutrophilic infiltrate, and vasculitis-like changes. These 2 histopathologic patterns of ND, early and late, resemble neutrophilic urticarial dermatitis (also known as neutrophilic dermatitis with systemic inflammation) and Sweet syndrome, respectively. Extensive workup did not reveal evidence of relapsed chronic myelogenous leukemia, infection, or a coexisting systemic inflammatory disease. Dasatinib was discontinued and the eruption gradually resolved over 2.5 months. Still in molecular remission (no detectable BCR-ABL gene fusion), dasatinib therapy was recommenced at 3-month follow-up. After 10 months, she complains of malaise and arthralgia, but no cutaneous symptoms. The evolution and slow resolution of this ND in lipo-lymphedematous skin implicate poor lymphatic clearance of factors, antigenic and/or toxic, involved in the pathogenesis of ND.