Differential Diagnosis of Genetic Disorders Associated with Moderate to Severe Refractory Eczema and Elevated Immunoglobulin E

The association of moderate to severe eczema and elevated plasma levels of immunoglobulin E is a characteristic not only of atopic dermatitis but also of various genodermatoses: hyperimmunoglobulin E syndromes, Omenn syndrome, Netherton syndrome, peeling skin syndrome type B, severe dermatitis, multiple allergies, and metabolic wasting syndrome, Wiskott-Aldrich syndrome, prolidase deficiency, Loeys-Dietz syndrome, IPEX syndrome, STAT5B deficiency, and pentasomy X. The clinical presentation of these genodermatoses -typically in children- is consistent with severe atopic dermatitis. Immunoglobulin E is elevated from birth and response to conventional treatments is poor. Diagnosis is further complicated by the fact that these genodermatoses often share other clinical manifestations and laboratory findings. We present practical guidelines for differentiating among these various entities, with the aim of helping physicians decide what type of genetic test should be carried out -and when- in order to establish a definitive diagnosis.