Neutrophilic Urticarial Dermatosis.

Neutrophilic urticarial dermatosis (NUD) is a rare form of dermatosis that is poorly understood. It was first described by Kieffer and colleagues as an urticarial eruption that is histopathologically characterized by a perivascular and interstitial neutrophilic infiltrate with intense leukocytoclasia and without vasculitis or dermal edema. NUD clinically presents as a chronic or recurrent eruption that consists of nonpruritic macules, papules, or plaques that are pink to reddish and that resolve within 24 hours without residual pigmentation. NUD is often associated with systemic diseases such as Schnitzler syndrome, lupus erythematosus, adult-onset Still's disease, and cryopyrin-associated periodic syndromes.