Herpes simplex virus central nervous system relapse during treatment of infantile spasms with corticotropin

Here we report an infant who had herpes simplex virus (HSV) encephalitis and sustained severe bilateral damage to the posterior frontal lobes, postcentral gyri, and the thalami despite intravenous acyclovir treatment. At 7 months of age, the patient developed infantile spasms and was treated with corticotropin injections. After 10 days of corticotropin treatment, she developed lethargy, fever, and opisthotonic posturing. Her cerebrospinal fluid again was positive for HSV DNA, indicating recurrent HSV encephalitis, and repeat MRI revealed new lesions of the right frontal, parietal, temporal, and occipital lobes. Immunosuppression by corticotropin may have led to the reactivation of the HSV encephalitis. Corticotropin should be relatively contraindicated for use when a patient has a history of HSV infection, or intravenous acyclovir should be administered concurrently.