Herpes infections.

Caused by herpes simplex viruses 1 (cold sores on lips) and 2 (sores on genitals). In HIV-infected patients, herpes simplex infections form chronic ulcers, often affecting face and sometimes the eyes; anal area often affected in homosexual males. Herpes infections are commonly found in people who are not infected with HIV; forming a cluster(s) of small, painful blisters, often, but not necessarily, on face.