A rash may occur after HIV infection, but it usually occurs in the acute or late stages of infection, and not all patients with HIV develop a rash. The difference between AIDS rash and common rash should be distinguished in terms of etiology, distribution location, traits and symptoms. 1. Etiology: AIDS rash is caused by HIV infection; common rash may be caused by local skin allergy, environmental temperature changes, etc.; 2. The common rash is mostly red, with various shapes, and may appear as ulcers and herpes when the condition worsens; 4. When you suspect that you are infected with HIV, you cannot judge simply from the rash, because not all AIDS patients will have a rash, so when you suspect that you are infected with HIV, you need to go to the hospital for further examination to determine.