Punctate Purpura Complicated with Immunoglobulin G4-related Disease.

Immunoglobulin G4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition affecting multiple organs; however, the involvement of skin lesions is rare. We herein report a 65-year-old man who presented with pruritic punctate purpura on both legs and elevated liver enzyme levels. Computed tomography showed enlargement of the pancreas and thickening of the bile duct wall. Magnetic resonance cholangiopancreatography showed diffuse irregular constriction of the main pancreatic duct, stricture of the lower common bile duct, and dilation after confluent stricture. A histopathologic examination of the pancreas and his enlarged salivary gland showed infiltration of IgG4-positive plasma cells. Ultimately, the patient was diagnosed with IgG4-RD.