Background: Both hyper-IgE syndrome and food allergies can result in the early onset of skin rash, eosinophilia, and markedly elevated serum IgE. Occasionally, it can be difficult to distinguish the 2 disorders. Most patients with hyper-IgE syndrome do not have food allergy.
Objective: To describe a child with cow's milk allergy associated with hyper-IgE syndrome manifesting as failure to thrive (FTT).
Methods: Epicutaneous skin prick test to cow's milk, CAP radioallergosorbent test, atopy patch tests, and double-blind, placebo-controlled milk challenge (DBPCMC) were performed.
Results: During initial presentation at 3 weeks of age, the circulating eosinophil count increased from 13,800/mm3 to 44,254/mm3 within 2 weeks while taking cephalexin. Despite treatment, he had worsening rash and FTT at 10 weeks of age with an IgE level of 8,454 U/mL. After changing from an infant milk formula with whey protein to an amino acid-based formula in combination with oral antibiotic treatment, his rash and growth velocity improved markedly within 2 months. IgE decreased to 2,747 U/mL. He remained clinically well for 12 months. He subsequently developed additional food and inhalant allergies with an increase in IgE to 12,150 U/mL. Cow's milk allergy was confirmed by epicutaneous skin prick test, atopy patch test, and DBPCMC.
Conclusions: Traditional prophylactic antistaphylococcal antibiotics, in combination with Neocate formula, were effective in treating the early skin manifestations of hyper-IgE syndrome and FTT in this infant. Cow's milk protein allergy should be considered in patients with hyper-IgE syndrome and FTT.