IgG4-related skin diseases: A brief review

Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized syndrome which shares similar pathologic, serologic, and clinical features in the affected organs. Subacute development of a mass or diffuse enlargement of the organ is a common presenting feature. It is more commonly seen in middle-aged or older men. Lymphadenopathy is common in them. Tissue infiltration with lymphoplasmacytic collection, predominantly of IgG4-positive plasma cells, accompanied by “storiform” pattern of fibrosis, obliterative phlebitis, and increased tissue eosinophils are the hallmark histologic findings. Rapid response to systemic steroids is characteristic. If present, the typical cutaneous findings such as papulonodules or plaques in the head-and-neck region may serve as an initial clue to the underlying systemic involvement in IgG4-RD. Hence, dermatologists need to be aware of this entity for early recognition of underlying organ involvement and thus the prompt management.