Herpes simplex encephalitis with relapse.

Three children are described in whom herpes simplex encephalitis (HSE) followed a clearly biphasic course. The secondary deterioration may be due to a resurgence of the viral infection and calls into question the adequacy of current treatment regimens for HSE. Alternatively, a postinfectious neuroallergic process may be active in which case immunomodulatory treatment might be more appropriate than further antiviral treatment.