Neutrophilic urticarial dermatosis without systemic disease: case report

Neutrophilic urticarial dermatosis (NUD) is an uncommon and not well-understood disease. We report a 24-year-old female with the persistent presence of pruritic and painful urticarial plaques unresponsive to conventional treatment. Histopathologically, it demonstrates a perivascular and interstitial neutrophilic infiltrate with leukocytoclasia without evidence of vasculitis or dermal edema consistent with neutrophilic urticarial dermatosis. Further investigations to rule out underlying autoimmune, autoinflammatory and genetic systemic disease were negative. Furthermore, the cutaneous eruption was resistant to multiple therapeutic interventions, including colchicine and dapsone treatment, and showed a significant response to treatment with anakinra, interleukin-1 receptor antagonist. Based on literature review, the case reported here is the second case with clinical and pathologic features of NUD without systemic disease and the first case of NUD that showed resistance to colchicine and dapsone treatment, with adequate response to anakinra.