Carbamazepine-induced interstitial pneumonitis associated with pan-hypogammaglobulinemia.

Carbamazepine remains a first-line drug for treatment of epilepsy in children. A wide variety of side effects have been attributed to its use, including a mild involvement of the immune system, usually a transient decline in IgA. Pulmonary complications, including interstitial pneumonitis, were mainly described in adults, and are considered rare side effects. In this report we describe the first pediatric patient who developed a severe interstitial pneumonitis and a pan-hypogammaglobulinemia 2 months after starting carbamazepine. A gradual resolution of symptoms and complete immune recovery was observed after the drug withdrawal, but 6 months later our patient still has a marked reduction in lung volumes and decreased exercise tolerance. We suggest that immunoglobulins should be carefully examined after carbamazepine initiation, particularly if the patient develops any sign of immunosuppression.