Itchy red spots on the body are mainly considered to be caused by allergic skin diseases, including urticaria, eczema, drug rash, atopic dermatitis and so on. The specific allergens are complex, including food allergies, drug allergies, environmental inhalant allergies, and contact substance allergies, etc., all over cause red spots on the skin with significant itching. In this case, you should go to a medical doctor in a timely manner. You can do an allergen alkaline test to clarify the allergen and avoid it. In terms of clinical treatment, oral antihistamines such as olopatadine hydrochloride tablets can be taken, and topical application of glycopyrrolate Sin or glucocorticoid drugs such as mometasone furoate ointment 1 time/day is applied for treatment, and alcohol needs to be avoided during treatment, and spicy and irritating foods, including raw onion, raw garlic, chili pepper, etc. need to be avoided.