Scratch urticaria is a type of skin allergy, while AIDS is caused by the human immunodeficiency virus and has a variety of symptoms, the presence of scratch urticaria is not diagnostic of AIDS. Therefore, urticarial urticaria is not a premonitory symptom of AIDS.1. Urticarial urticaria: It usually occurs at any age and has no obvious cause. Patients’ skin is sensitive to external mechanical stimuli, and when nails or other blunt instruments scratch the skin, strips of elevated scratches will appear on the stimulated area, accompanied by itching, which will subside after half an hour or so. If bathing with hot water, the itching symptoms will be aggravated and the course of the disease will be prolonged. If necessary, take antihistamines under the guidance of a doctor and prohibit the use of skin vasodilators; 2. AIDS: mainly through sexual transmission, mother-to-child transmission and blood transmission, the incubation period is long and most infected people have no symptoms. The acute infection period can be characterized by fever, fatigue, myalgia, swollen lymph nodes and general discomfort and other flu-like symptoms, but also a scattered rash, mainly manifesting as a torso rash, rose rash, and swollen lymph nodes in the neck, axilla and occiput. The skin reaction of AIDS is mainly divided into inflammatory and infectious. Inflammatory is similar to dermatosis, pruritus with papules, atopic dermatitis, seborrheic dermatitis, psoriasis, hyperpigmentation, etc. Infectious is caused by severe infections and condition-causing bacteria, such as herpes simplex, herpes zoster, warts, and cellulitis, folliculitis, etc. In addition to the above symptoms, there are also symptoms such as cough, coughing, dyspnea, nausea, vomiting, and diarrhea depending on the individual’s constitution. As mentioned above, the clinical symptoms of AIDS are diverse and the skin reaction is not specific, so it needs to be differentiated from urticaria. Scratch urticaria, for example, is usually predominantly itchy and has erythematous, windy patches, accompanied by red or white bumps along with the signs of scratching. The skin reaction to AIDS is mostly a raised-appearing red papule with mild itching and pain. In addition, there is no specific treatment for AIDS. Antiviral drugs can be applied for treatment, commonly used drugs include tenofovir, lamivudine, efavirenz, etc. It is also necessary to strengthen nutrition and pay attention to rest. Since AIDS is mainly transmitted sexually, you should avoid having unclean sex to avoid infecting others. To diagnose AIDS, HIV testing is required and needs to be differentiated from congenital or other causes of immunodeficiency syndrome.