Cutaneous adverse reactions to
antiepileptic drugs (AEDs) are usually easily recognized in daily clinical practice when they manifest as a morbilliform or maculopapular
rash within the first few weeks after introducing an AED.
Valproate (VPA)-induced
encephalopathy is a rare but serious complication, presenting with impaired consciousness, with or without
hyperammonemia, normal liver
enzymes, and normal serum level of VPA. A 2-year-old Caucasian boy with severe
developmental disability and pharmacoresistant
epilepsy presented with
fever, generalized erythrodermia, and
encephalopathy, which resolved after discontinuation of
valproate.
Sodium valproate (30 mg/kg/day) was introduced 5 months previously, as the third
drug in combination with
vigabatrin and
levetiracetam, due to frequent daily
seizures. The clinical condition of generalized erythrodermia and
encephalopathy was recognized by the treating physician as a possible adverse reaction to VPA: with the Naranjo scale it was probably associated with VPA (six points) and possibly associated with
vigabatrin and
levetiracetam (three and two points, respectively). After
valproate withdrawal, the patient recovered completely. This case is of interest because erythrodermia was a clue to the recognition of
valproate-related adverse reaction with severe central nervous system involvement without
hyperammonemia and with normal liver
enzymes--a very rare occurrence.