Provide an update of the developments in IgG4 related disease within the last year in terms of nomenclature, diagnostic criteria and clinical features.The number of diseases associated with IgG4 related disease continues to grow. The entities of idiopathic orbital inflammation, idiopathic cervical fibrosis, eosinophilic angiocentric fibrosis, reactive nodular fibrous pseudotumor, sclerosing mesenteritis, and membranous glomerulonephritis should all be added to the list of diseases associated with the IgG4 related disease spectrum. The issues of nomenclature and diagnostic criteria for IgG4 related disease have important recent developments as well.The diagnosis of IgG4 related disease continues to be challenging. Increasing recognition of IgG4 related disease has led to a large body of literature on organ sites of involvement. Understanding how the disease manifests itself is critical to diagnosis and ultimately treatment.