Psoriasiform eruption induced by anticonvulsants.

We present findings from three patients who experienced a psoriasiform eruption apparently due to the antiepileptic agents sodium valproate and carbamazepine. The causal relationship between the drug and the eruption has been based mainly on circumstantial evidence and is further strengthened by the positive result of one or two in vitro tests: the macrophage migration inhibition (MIF) test and the indirect rat mast cell degranulation (MCD) test. Sodium valproate and carbamazepine, antiepileptic drugs that are associated with a relatively low rate of adverse cutaneous reactions, should be added to the growing list of drugs that produce psoriasiform eruptions. A drug-induced psoriasiform eruption due to these drugs seems to be more common than previously reported. Physicians should be aware of this type of reaction. Early detection of these cases has practical importance since the identification and elimination of the causative drug is essential for therapy success.