Hyper IgE syndrome is the rare combination of very high serum immuno globulin E (IgE) levels with immune deficiency. The high concentration of IgE causes the atopic features, especially severe eczema. Mutations in the STAT3 gene are responsible for the deficient translation of the cytokine signals in effective immune responses. Patients are thus prone to severe destructive staphylococcal infections of skin and lungs, often with surprisingly few clinical symptoms. Other systemic consequences are characteristic facial features with retention of primary teeth, bone fractures from mild trauma, scoliosis and vascular aneurysms. Management includes control of the allergic features and early and aggressive treatment of infections.