Severe Atopic Dermatitis: Clinical Confusion With Hyper IgE Syndrome.

Hyper IgE syndrome (HIES) is a rare primary immunodeficiency characterized by chronic eczema, recurrent staphylococcal infections on the skin and pulmonary system, and high serum IgE concentrations. The first clinical sign of HIES is eczema, usually in early infancy. Severe atopic dermatitis (AD) may also mimic HIES with findings of eczema, high serum immunoglobulin E levels, and eosinophilia. Therefore, differential diagnosis may be difficult. Here, we present a case with eczematoid skin rashes, asthma, elevated serum IgE levels, and skin infections that started in infancy and were followed for nine years by the pediatric allergy and immunology clinic with the diagnosis of HIES, but in fact, had severe AD. Because the patient had no recurrent infections that would suggest immune deficiency during his clinical follow-up, other than the skin infections at the time of diagnosis. In addition, the patient had no non-immunological symptoms of hyper IgE syndrome.