Arthritis, eosinophilia, and autoimmune liver disease: a diagnostic challenge.

Autoimmune hepatitis (AIH) is a chronic liver disease of unknown etiology. It is composed of immune-mediated liver injury and significant immunological aspects. Arthritis can be observed in patients with AIH before recognition of the disease, which can lead to a diagnostic challenge. Although there are few reported cases in literature, peripheral blood eosinophilia might also play a part in such diagnosis. We report an intriguing case of a 41-year-old man who presented to our service with arthritis and eosinophilia as initial manifestations and was eventually diagnosed with overlap syndrome: AIH and primary sclerosing cholangitis. The present report aims to include eosinophilia among the clinical features of AIH, highlighting the possibility of its detection before the onset of either articular or hepatic disturbances.