Alum refers to alum, the harm to the body skin is not clear, the specific use of medication as prescribed by the doctor. Alum is made of sulfate alumite mineral alumite by processing and refining of Chinese medicine, external detoxification and insecticide, dry dampness and itching; internal use of antidiarrheal, expectorate wind and phlegm. Externally, it is used for eczema, scabies, and pus in the ear; internally, it is used for prolonged diarrhea, blood in the stool, disintegration (excessive menstrual flow or dripping), and epilepsy and madness. The adverse effects of this herb are not clear, and it should be used with caution for people with weak stomachs, and avoided for people without dampness or heat. Externally, it can be used in appropriate quantities, powdered and applied to the affected area or washed with water; since alum is astringent and difficult to swallow, it should not be taken internally in excessive amounts. There is no research on the harmful effects of this product on the skin. Specific medication should be carried out under the guidance of a specialist, not unauthorized use of medication, so as not to delay the condition.