Radiological aid to clinical diagnosis of Schnitzler's syndrome: multimodality imaging approach.

Schnitzler's syndrome is a rare combination of chronic urticaria, fever of unknown origin, disabling bone pain, and monoclonal gammopathy. We report a case with an unusual radiological manifestation as a solitary sclerotic lesion of the right iliac bone. Its main features on conventional radiography, computed tomography, and magnetic resonance imaging are described, and the main radiological differential diagnoses are discussed to help with the characterization of this syndrome, which requires a combination of clinical, laboratory, and radiological data. On the other hand, although our patient had an excellent clinical response to anakinra, the sclerotic lesion remained unchanged on follow-up X-ray examinations.