Most cases of herpes simplex infection are diagnosed on the basis of clinical features and symptoms of the condition, whether the infection is genital herpes or orofacial herpes.

Diagnosis

The diagnosis of herpes simplex involves:
 

1. A detailed history of recent sexual contact and whether it was with an infected person or someone at risk of being infected. Details of any previous similar infections or history of cold sores among family members or partners are also obtained. The infection may be spread through unprotected vaginal, anal or oral intercourse or through skin-to-skin contact with an infected individual. The infection may also pass from an infected mother to her newborn.

2. Clinical examination of the sores. The sores of herpes simplex infection have certain distinguishing features which include:

   • They are multiple or clustered.
   • In the case of oral herpes, blisters, bumps and a tingling sensation may occur across the site of infection which may include the mouth, lips, gums and throat.
   • In the case of genital herpes, painful, fluid-filled blisters called vesicles may be present.

3. A swab is used to collect a sample of fluid from blisters. The swab is made up of an absorbent material such as cotton placed on the tip of a flexible stick or wire. The sample is then sent to the laboratory for testing and the person is screened for other sexually transmitted infections. If an individual is infected with the herpes simplex, they are positive for the presence of antibodies to the virus.

4. Diagnosis needs to be confirmed in pregnant women as well as in people suspected to have HIV infection or AIDS. People with lowered immunity, for example, due to radiation therapy or chemotherapy also need to be screened for herpes infection.