Immunologic aspects of phenobarbital hypersensitivity.

Seven patients with hypersensitivity reactions to phenobarbital are described. Clinical manifestations consisted of fever and pruritic skin rash, often associated with adenopathy and conjunctivitis. Reexposure to phenobarbital or other anticonvulsants resulted in redevelopment of symptoms. In vitro lymphocyte stimulation studies with anticonvulsant drugs suggested a cell-mediated hypersensitivity reaction to phenobarbital.