Figure 1From: Emerging concepts in the diagnosis and treatment of patients with undifferentiated angioedema Type I hypersensitivity is mediated by IgE and induces mast cell degranulation. FcεRI, high-affinity IgE receptor; IgE, immunoglobulin E; IL-4, interleukin 4; IL-5, interleukin 5; TNF-α, tumor necrosis factor-alpha [4].Back to article page