IgG4-related disease: long-term natural history and management of a relapsing multisystem disease entity.

Although awareness of IgG4-related disease has grown over the past decade, with earlier diagnosis and treatment, understanding of its natural history over the long term and the optimal management remains unclear. We report the case of a 48-year-old man who presented with a pancreatic pseudotumour causing bile duct obstruction with coexisting autoimmune hepatitis and multisystem involvement. His symptoms settled on steroids and maintenance with azathioprine was commenced, however periodic relapses occurred involving multiple organs. A timeline-relating IgG4 levels, clinical features and immunosuppressive therapy are presented. The protean and relapsing-remitting nature of this condition is emphasised, and a brief review of long-term therapeutic options is provided.