One of the most noticeable changes that may prompt concern is the appearance of bumps, blisters,
ulcers, or sores. These can occur on or around the genitals, anus, lips, or other areas of skin that have had contact with an infection.
Several STIs can cause lesions, but their appearance varies considerably.
Genital herpes may cause clusters of small blisters that break open and form painful sores. Some people experience tingling, itching, or burning before the lesions appear. Others have symptoms so mild that they mistake them for an ordinary skin irritation, an ingrown hair, or a small cut. Herpes can also be transmitted when no obvious sore is present.
Syphilis may initially cause a sore called a chancre at the site where the infection entered the body. It is often firm and painless, which means it can go unnoticed, particularly when it develops in an area that is difficult to see. The sore may disappear without treatment, but the infection can remain and progress to later
stages.
