Assessment of genital herpes

Genital herpes is a sexually transmissible infection (STI) caused by either herpes simplex virus (HSV) 1 or 2. HSV 1 is a common cause of initial infection, while recurrent genital herpes is usually caused by HSV 2. HSV (typically HSV 1) is also transmissible via autoinoculation or from contact with oral or other HSV lesions. Perinatal transmission can occur in neonates; see Neonatal herpes simplex infection. For children with suspected anogenital herpes, seek expert advice; see also STIs in children.

Consider HSV in the diagnosis of any acutely painful genital lesion. The majority of patients with genital herpes are asymptomatic and therefore remain undiagnosed.

Before starting antiviral therapy, collect a swab from the base of a lesion or deroofed vesicle for HSV type–specific nucleic acid amplification testing (NAAT) (eg polymerase chain reaction [PCR]). Herpes serology is not recommended for screening asymptomatic people and should be limited to specific situations (eg an asymptomatic pregnant partner of a newly diagnosed person) – seek expert adviceOng, 2023.

Perform investigations for other STIs (including HIV, syphilis, Neisseria gonorrhoeae and Chlamydia trachomatis). Contact tracing is not required for genital herpes. For general principles of STI management, see also Principles of STI management.

Patients with undiagnosed HIV infection may present initially with severe genital herpes. For patients who need to be started on antiretroviral therapy for HIV, see Genital herpes in adults with HIV infection.