Red forehead can consider the following aspects caused, such as whether local collision, abrasion and other external factors can cause skin redness in the forehead, whether there is abnormal contact with other foreign objects at the forehead, such as towels, hair cards, hair bands, antipyretic patches, sweat towels, etc.. See if the local rash border is clear, whether accompanied by itching and other symptoms, if the above symptoms, consider the possibility of local contact dermatitis, it is recommended to take oral antihistamine drugs orally and glucocorticoid ointment topical rub treatment. If, in addition to the red forehead, the entire face can be accompanied by erythema and local skin heat, consider whether the patient has ever consumed photosensitive foods such as parsley and celery before sun exposure, resulting in solar dermatitis, erythema of the face, etc. When the above symptoms appear, you should look for possible causative factors as much as possible, and actively and effectively remove them to avoid the recurrence of the disease.