Schnitzler syndrome is a clinical entity of unknown etiopathogenesis and is
an unusual cause of chronic urticaria. It is characterized by the presenta
tion of a monoclonal band, especially IgM, as well as fever, asthenia and a
rthralgia. We present the case of a 48-year-old man with 5 years of recurre
nt urticarial lesions, slight itching, as well as lip, face and occasional
pharyngeal edema. The patient had also suffered from fever and right hip an
d left knee arthralgia. The protein electrophoresis and the immunoelectroph
oresis presented an IgG band and a slight lambda band, which is suggestive
of a monoclonal gammopathy. The bone marrow examination showed a slight inc
rease in the lymphoplasmatic cells. The marrow biopsy was negative. in orde
r to rule out tumorous, infectious and rheumatic processes as well as colla
gen diseases, other complementary examinations were performed with negative
results. The diagnosis of Schnitzler syndrome as a cause of chronic urtica
ria requires a thorough study in order to rule out other systemic processes
provoking the same symptoms.