Anticonvulsant hypersensitivity syndrome: is there a role for immunomodulation?

The anticonvulsant hypersensitivity syndrome (AHS) is an idiosyncratic immunologic reaction to certain anticonvulsant medications, in which internal organ involvement may lead to fatal multisystemic failure. This syndrome has been associated with the use of aromatic ring-containing agents such as phenytoin, carbamazepine, or phenobarbitone. Clinically, this condition presents with the classic triad of fever, rash, and lymphadenopathy. We review the existing literature on AHS pathogenesis and illustrate a case complicated by liver dysfunction where the use of N-acetylcysteine (N-AC) and intravenous immunoglobulin (IVIG) may have altered the course of the disease. The rationale of suggesting N-AC and IVIG for the treatment of this syndrome relies on the theoretical synergistic effects of the two agents. Although treatment for this syndrome remains controversial and relies heavily on anecdotal evidence, the progression of hepatic injury may be prevented by the addition of N-AC. The scavenging properties of N-AC may palliate and possibly prevent free radical-mediated liver damage. In addition, IVIG may effectively modulate the overreactive immune system in AHS. We discuss the possible role of using immunomodulating agents for the treatment of this syndrome and suggest that alternative regimens should be given special consideration especially in those critical clinical situations where supportive measures appear to be unsuccessful.