Schnitzler's syndrome: A female elderly case presenting intractable non-pruritic febrile urticarial rush

Schnitzler's syndrome is an acquired autoinflammatory disease characterized by chronic urticarial rash and monoclonal gammopathy (predominantly IgM type). A 75-year-old Japanese woman complained of high fever and non-pruritic urticarial rash appearing almost every day for 3 years. Her abnormal laboratory data included leukocytosis and neutrophilia with elevated erythrocyte sedimentation rate and C-reactive protein level. Hyperglobulinemia of IgA and IgM was also noted. Histological analysis revealed perivascular and interstitial neutrophilic infiltration without any signs of vasculitis. Immunofixation analysis confirmed IgM-kappa-type monoclonal gammopathy. Oral prednisolone initially improved her symptoms, but recurrence was observed upon its tapering. The addition of colchicine successfully controlled her symptoms and allowed a reduction in the dose of systemic steroid.