According to temporal criteria, our case involved a patient with late latent syphilis, in which the immunodepression related to the mild advanced HIV infection (negative p24 antigen, CD4/CD8 ratio 0.3) contributed to the appearance of an atypical florid and scattered mucocutaneous rash as a rare relapse of syphilis during late latent stage. This evidence concerns the gene CD4 and syphilis.