A case of autoimmune pancreatitis with metachronous appearance of idiopathic thrombocytopenic purpura.

Autoimmune pancreatitis (AIP) is often associated with systemic disorders, but a case accompanied with idiopathic thrombocytopenic purpura (ITP) is very rare. A 67-year-old man was referred to our institution with complaints of abdominal pain and jaundice. Multiple images showed diffuse enlargement of the pancreas, narrowing of the main pancreatic duct, stenosis of the lower common bile duct and thickness of the anterior wall of the abdominal aorta. Serum levels of IgG and IgG4 were elevated and a diagnosis of AIP was made based on the Japanese criteria. The pancreatic lesion and serum markers responded well to steroid therapy. A year after withdrawal of steroids, the peripheral blood platelet levels gradually decreased to 5.8 × 10(4)/μl. With elevated serum PAIgG levels and exclusion of other causes, we diagnosed ITP. Immediately after restarting steroid therapy, the platelet level in the peripheral blood recovered.