Some STIs can cause patchy hair loss. This can happen in the later stages of syphilis. You may also get a fever, sore throat, or a rash that doesn’t itch. It’s important to take medicine to cure syphilis. That’s because even though your symptoms may get better without treatment, the STI stays in your body. Syphilis can go on to hurt your eyes, heart, and brain. If you use a latex male condom, you can lower your chances of future STIs.