Hyper IgE syndrome is characterized by recurrent skin and lung infections and an eczematous pruritic rash. Which finding is NOT typically seen?

• A. Thrombocytopenia
• B. Elevated IgE levels
• C. Eczema‑like rash
• D. Recurrent pneumonia

Answer: (A)

Hyper IgE syndrome presents with very high IgE levels, an eczematous pruritic rash, and recurrent Staphylococcus skin and pulmonary infections, often including pneumonia. The reason the finding described as not typically seen is thrombocytopenia. Platelet low count is not a hallmark of this syndrome; in fact, it helps differentiate it from other immunodeficiency conditions like Wiskott-Aldrich, which features eczema plus thrombocytopenia.

The elevated IgE reflects immune dysregulation, and the eczema-like rash plus recurrent pneumonia fit the classic pattern. Recurrent pneumonia arises from impaired neutrophil recruitment to infection sites due to a STAT3-driven defect in T-helper 17 development, leading to susceptibility to staph infections and to pneumonias that can form pneumatoceles. So, while the rash, high IgE, and recurrent pneumonia are expected, thrombocytopenia is not.