What are the recommended diagnostic tests for confirming genital herpes in a patient with typical symptoms?

Guideline-aligned answer with reasoning, red flags and references. Clinically reviewed by Dr Kola Tytler MBBS CertHE MBA MRCGP.

Posted: 16 August 2025Updated: 16 August 2025 Guideline-Aligned (High Confidence) Clinically Reviewed
Dr Kola Tytler MBBS CertHE MBA MRCGPClinical Lead • iatroX

To confirm a diagnosis of genital herpes in a patient presenting with typical symptoms, the recommended diagnostic test is to take a virology swab from any active genital or extragenital lesions for herpes simplex virus (HSV) detection. This direct detection method is the primary approach in clinical practice and should be performed promptly when lesions are present to maximise diagnostic yield .

Polymerase chain reaction (PCR) testing of the swab is preferred due to its high sensitivity and specificity, allowing for accurate detection and typing of HSV-1 or HSV-2, which is important for clinical management and counselling .

Serological testing using HSV type-specific serology may be considered in certain cases, such as when lesions are not present or for screening sexual partners to assess risk of acquisition, but it is not the first-line diagnostic tool for confirming active infection .

In summary, the key diagnostic step is lesion swabbing with PCR testing for HSV DNA, supported by type-specific serology when appropriate. This approach aligns with UK clinical guidelines and is supported by international literature emphasizing molecular methods for accurate diagnosis ; .

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