Carbamazepine Hypersensitivity

In approximately five to ten percent of patients, carbamazepine treatment is associated with carbamazepine-induced hypersensitivity reactions, which are generally cutaneous in nature. It is also rarely (0.01 to 0.1 percent of patients) associated with severe reactions, including Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN).

Symptoms of carbamazepine-induced SJS/TEN generally occur within one to three weeks after beginning carbamazepine treatment, and are caused by immune-mediated keratinocyte cell death, leading to detachment of the skin. In SJS, less than 10% of the body surface is affected, and it is fatal in up to 10% of cases. In TEN, which is fatal in up to 50% of cases, greater than 30% of the body’s surface is affected. Both conditions are characterized by epidermal detachment and severe mucous membrane erosion over the affected area of the body.