Transient hypogammaglobulinemia after antiepileptic drug hypersensitivity

The case is described of a 32-month-old male with transient but long-lasting severe hypogammaglobulinemia subsequent to multiple drug hypersensitivity. The patient had remarkably decreased immunoglobulin levels (IgG 136 mg/dL, IgA 11 mg/dL, and IgM 10 mg/dL) 3 months after hypersensitivity to phenobarbital and phenytoin. Immunological study revealed reduction of B-cell count and decreased lymphocyte proliferation response to Staphylococcus aureus Cowan. IgM secretory response to pokeweed mitogen and S. aureus Cowan was almost preserved, whereas IgG secretory response was markedly decreased. The patient was treated with intravenous immunoglobulin, although recurrent infection was not observed before treatment. His immunoglobulin levels became normal more than 5 years after the onset of hypogammaglobulinemia.