Autoimmunity-related neutrophilic dermatosis: a newly described entity that is not exclusive of systemic lupus erythematosus.

Neutrophilic dermatoses have long been known to be associated with autoinmune systemic diseases. Recently, a small number of cases of a disorder distinct from Sweet syndrome or bullous lupus erythematosus (LE) have been described as specifically related to systemic LE under diverse terms, including nonbullous neutrophilic dermatosis, nonbullous neutrophilic LE, and Sweet-like neutrophilic dermatosis. We describe 7 patients that developed urticarial lesions in the context of a known or concurrently diagnosed autoimmune connective tissue disease. Of a total of 7 patients, 6 were afflicted by systemic LE and 1 by rheumatoid arthritis and secondary Sjögren syndrome. Histological findings in all patients included an interstitial and perivascular neutrophilic infiltrate with leukocytoclasia, vacuolar alteration along the dermal-edidermal junction, and no vasculitis. Most patients had active systemic disease at the time of the cutaneous eruption. Skin lesions resolved rapidly after the administration of immunomodulating agents. In conclusion, we provide additional evidence of the existence of a recently defined nonbullous neutrophilic dermatosis in the context of autoimmune connective tissue diseases and propose the term autoimmunity-related neutrophilic dermatosis as an appropriate designation. Furthermore, we believe that this entity should prompt physicians to screen the presence of an active systemic disorder in afflicted patients.