Diphenylhydantoin sensitivity. a syndrome resembling infectious mononucleosis with a morbilliform rash and cholestatic hepatitis.

A ten-year-old boy presented with an illness resembling infectious mononucleosis associated with an unusual skin rash and marked cholestatic hepatitis. This combination represents a rare reaction to diphenylhydantoin. Few reported cases have been published. The illness commences from three to seven weeks after starting therapy. Although one death has been reported, other cases have shown complete recovery. Early recognition of the combination of symptoms and cessation of drug therapy is essential.