The black marks left after allergy, i.e. hyperpigmentation, localized pigmentation caused by improper care and treatment can be treated by daily protection, topical medication and chemical peeling. 1. Daily protection: daily attention should be paid to sunscreen, ultraviolet light can induce melanocyte proliferation, aggravate hyperpigmentation, you can choose parasol, topical sunscreen, etc.; avoid scratching, friction and other mechanical stimuli. 2. Topical medication: choose medication with decolorization and exfoliation effects, such as vitamin A acid cream, hydroquinone cream, etc. 3. Chemical skin resurfacing, such as professional concentration of salicylic acid, fruit acid, etc., can promote the epidermis, dermis superficial cell exfoliation and regeneration, improve the appearance of hyperpigmentation. The above medications and treatments should be carried out under the guidance of specialized physicians. If treatment is needed, it is recommended to consult a regular hospital and follow the doctor’s instructions for standardized treatment.