The incubation period is usually from 3 to 6 days but may be longer.
In males, primary lesions usually occur on the penile shaft, prepuce or glans or the anal region.
In females, primary lesions occur commonly on the labia, clitoris, introitus and vagina. The cervix is involved in at least 50% of cases. In about 25%, the cervix is the only site of lesions and these cases may be asymptomatic.
Lesions may occur in the mouth or throat following oral sex.
Lesions may occur on the fingers, buttocks, torso and the eyes as a result of autoinoculation. Transmission may also occur on fomites.
Lesions are usually preceded by a 12-24 hour prodromal period characterised by local hypersensitivity or discomfort.
Multiple vesicles appear. They are surrounded by an areola of erythema. After 24 to 72 hours, the vesicles rupture to form painful superficial ulcers. Lesions of varying age and size coexist. Symptoms persist for 1 to 3 weeks. In 75% of cases, regional lymph nodes are enlarged and tender for up to 6 weeks.