The formula of Erwei Puatoxan is Xionghuang and Alum. This formula is from “The Golden Annals of Medicine – Essentials of Surgical Methods” and is composed of Xionghuang and Alum. In the formula, Xionghuang is pungent, warm and poisonous, detoxifying and drying dampness, killing worms and stopping itching, and removing evil flesh; alum is sour, astringent, cold and non-toxic, with the effect of clearing heat and detoxifying (removing heat and toxicity in the body), drying dampness and killing worms, stopping bleeding and restraining sweating. The application of the two drugs together, detoxification, extraction, disinfection, toxicity efficacy is stronger, drying dampness, insecticide, itching power is more significant. It is mainly used in the treatment of contact dermatitis, herpes zoster, eczema and other diseases. At present, there is no relevant literature and reports on the adverse reactions and contraindications of Erweipuatoxin. If patients need to use Erwei Puatoxan, it is recommended to use under the guidance of a doctor to avoid adverse reactions, so as not to delay the condition.