1 It's usual to see only a rash during phi without fever or any other symptom?
2 If so, it means that the infected naive will be more sensible to develop rashes during the treatments for hiv (ex if he starts or switch a treatment)?
It is very unusual to see only a rash during primary HIV infection. The presence of a rash during primary HIV infection would not suggest to me that rashes would be more likely in the future. In two of the largest studies done of people with acute HIV infection the rate of rash was 56 and 69% (There were many other symptoms as well, 11 different symptoms on average). These studies did not look at subsequent risk of rash. If you have had an exposure you should be tested in any case because some people have minimal symptoms with primary HIV infection. Good luck. GP