Allergic rash is a common dermatological symptom caused by an abnormal immune response of the body due to allergic factors. Allergic rash clinical symptoms are relatively more, most patients will appear erythematous papules, and accompanied by itching symptoms, common diseases for allergic contact dermatitis, urticaria and drug rash, etc., and its condition type is relatively more complex. For allergic rashes need to try to remove the cause of the cause of the conditioning and treatment, can be used under the guidance of a doctor to treat drugs, such as dexamethasone, loratadine, etc., the majority of patients with the use of drugs after clinical symptoms will gradually disappear. Suffering from allergic rashes, it is recommended to go to the regular hospital as soon as possible to do the relevant examination, under the guidance of the doctor for treatment, to avoid aggravation of the condition.