Red rashes on the body may be related to contact dermatitis, urticaria, eczema and other diseases, which need to be treated with anti-allergy and anti-inflammatory drugs respectively. 1. Contact dermatitis: first of all, keep the local skin clean and avoid re-exposure to suspected allergens or irritants. Secondly, anti-allergy medication should be given, such as topical Denard cream, oral chlorpheniramine maleate tablets and so on. 2. Urticaria: Avoid re-exposure to allergens, and at the same time give antihistamine medication, such as oral loratadine tablets, ebastine tablets and so on. Can also be combined with calcium gluconate, vitamin C auxiliary treatment. 3. Eczema: first of all, we should find out the causative factors as far as possible, and try to remove them, followed by targeted anti-inflammatory and anti-allergy medication, such as topical mometasone furoate cream, oral levocetirizine capsules, and so on. Scratching and irritation must be avoided during treatment. Due to the different causes of the disease and different treatment modalities, it is important to have a doctor’s consultation before treatment, and medication should be prescribed by the doctor.