The rash is not a clinical characteristic of AIDS. The diagnosis of AIDS is not made by the clinical symptoms and signs of the patient, but by rigorous laboratory tests. If a patient has had unsafe high-risk sex or has been in contact with an HIV-infected person, it is recommended that he or she should have a blood test every 3-4 weeks until the diagnosis is confirmed. Because HIV infection does not produce antibodies immediately, it needs to accumulate to a certain amount of virus before it can be detected in the laboratory. Clinically, fever and rash are mainly considered as symptoms caused by viral infections, such as early childhood rash, scarlet fever, rubella, measles, etc. Therefore, fever and rash may not necessarily be AIDS.