Thymic hypoplasia associated with isotretinoin embryopathy

A newborn had isotretinoin embryopathy, including thymic hypoplasia. Evaluation of her immune functions demonstrated progressive attrition of T cells over the nine weeks until her death due to pneumonia. These studies strongly suggest an insult by isotretinoin to the immune system. Immune abnormalities may predispose infants with isotretinoin embryopathy to infection and contribute to their high mortality.