Kimura's disease or IgG4-related disease? A case-based review.

Kimura's disease usually presents with benign painless soft tissue swelling around the head and neck areas with eosinophilia and high immunoglobulin E (IgE) levels. IgG4-related disease is characterized by fibrosis and sclerosis of the involved organs, with infiltration of IgG4-positive plasma cells. There are some similar clinical manifestations of these two diseases, with eosinophilia or high IgE levels often found in patients with IgG4-related disease. However, the relation between these two diseases is not well known. We report a 23-year-old man who had multiple neck lumps for longer than 1 year. He had remarkable eosinophilia and elevated serum IgE levels. Biopsy of his lymph nodes suggested the diagnosis of both Kimura's disease and IgG4-related disease. In this article, we discuss the relationship between Kimura's disease and IgG4-related disease. We also suggest a possible model ("allergen-specific immunotherapy") to illustrate our view that an increase in IgG4-positive plasma cells is an epiphenomenon of Kimura's disease.