We know that one of the causes of diseases such as urticaria and contact dermatitis is an allergic reaction caused by the patient’s exposure to specific allergic triggers. So how can we avoid allergies? I will talk to you about it below. The general method of avoiding allergen triggers can be summarized in four words: avoid, avoid, substitute, and move. Avoidance means avoiding contact with all suspected or known allergic triggers. This refers to all allergic inhalation, ingestion, or exposure. For example, whenever an asthma attack is caused by inhalation of a certain insecticide, you should do everything possible to avoid contact with that insecticide. Avoidance is the avoidance of all suspected or known allergens, mainly in terms of food and medications. For example, if the patient can induce urticaria after eating shrimp or crab, he should avoid eating the above-mentioned foods; if the patient takes sulfonamide drugs that cause fixed drug rash, he should also avoid taking sulfonamide. Substitution means that if the patient is allergic to a certain drug or food, but for some objective reason cannot not apply it, he/she should try to find a drug or food with similar effects and no allergy to the patient to replace it. For example, if the patient is allergic to penicillin, but the condition requires penicillin treatment, erythromycin and other drugs with similar effects to penicillin and no allergy to the patient can be used instead. Removal means that for certain known allergens that are in frequent contact with the patient, once identified, they should be removed from the patient’s living environment. For example, if a patient is allergic to the fragrance emitted from a camphor box, or to the paint of a new type of furniture in the room, it should be moved out early. Often can receive unexpected results. As allergic patients your allergic triggers are varied, there are many patients whose allergic factors are difficult to be absolutely avoided. For example, house dust, pollen, mold, house mites, smoke, etc. are scattered everywhere and exist in large quantities in the air. Therefore, for some allergens that are difficult to avoid, patients can use atopic desensitization therapy.