Key clinical Message Stevens-Johnson Syndrome (SJS) is serious conditions that happen as a result of infection, side effects to medications or of unknown etiology. Carbamazepine is one of common medication that can cause (SJS). Good history taking is crucial if clinically indicated treatment with carbamazepine is there. We would like to Alert all physicians that carbamazepine should be avoided in any patient with a previous history of drug reaction like mast cell activation syndrome.