Stevens-Johnson (SJS) syndrome belongs to a group of severe drug rashes, which are caused by drug allergy and may involve oral-mucous membrane, skin and eyes as a manifestation of erythema multiforme. A variety of AEDs, such as carbamazepine, can effectively control the disease, but may cause such serious adverse reactions. SJS is characterized by high fever, malaise, rapidly developing and severe maculopapular and skin lesions, as well as mucosal involvement, and causes about 5% of deaths. Especially in children, it can have serious clinical consequences. It has been suggested that a specific allele of the human leukocyte antigen HLA-1502 is associated with SJS in the Han Chinese population, and it is therefore recommended that the Han Chinese population should be screened for this gene before starting allergy-prone AEDs. If a patient develops SJS syndrome as an adverse drug reaction, the consequences are often serious, especially in children and adolescents, and the risk of death is high. Therefore, before applying allergy-prone drugs, front-line clinicians usually inform the family of the possibility and risk of SJS, and ask the patient in detail whether there is a history of food and drug allergy to prevent the occurrence of cross-allergy. As medical workers, we should anticipate all kinds of hidden dangers and risks in the process of medical activities, and have the responsibility to remind and explain to patients and their families as early as possible, because patients have the right to know and should be allowed to make their own choice of medication or not in an informed manner. Doctor-patient communication is a technology and an art, actively doing “prevention before it happens” can often effectively reduce the occurrence of tragedies caused by doctor-patient conflicts to a large extent!