7. Rash
A rash can be caused by many different conditions, including STDs like HIV and syphilis. A red or red-brown rash with sores might point to syphilis, while a more generalized rash accompanied by dry skin and/or itching rash may point to HIV. When a rash appears as a result of HIV, it is usually because the virus has destroyed enough immune cells to allow for an opportunistic infection in the body. Herpes can also cause a small, itchy rash anywhere the body.