The frequency and severity of recurrent outbreaks vary greatly between people. Some individuals' outbreaks can be quite debilitating, with large, painful lesions persisting for several weeks, while others experience only minor itching or burning for a few days. Some evidence indicates genetics play a role in the frequency of cold sore outbreaks. An area of human chromosome 21 that includes six genes has been linked to frequent oral herpes outbreaks. An immunity to the virus is built over time. Most infected individuals experience fewer outbreaks and outbreak symptoms often become less severe. After several years, some people become perpetually asymptomatic and no longer experience outbreaks, though they may still be contagious to others. Immunocompromised individuals may experience longer, more frequent, and more severe episodes. Antiviral medication has been proven to shorten the frequency and duration of outbreaks. Outbreaks may occur at the original site of the infection or in proximity to nerve endings that reach out from the infected ganglia. In the case of a genital infection, sores can appear at the original site of infection or near the base of the spine, the buttocks, or the back of the thighs. HSV-2-infected individuals are at higher risk for acquiring HIV when practicing unprotected sex with HIV-positive persons, in particular during an outbreak with active lesions.
STI and sexual health expert Michael Asher (who is also CEO at Better2know, the company behind the STI testing for E4's The Sex Clinic) explains what we all should know about oral herpes. He says, "With 3.7 billion people under the age of 50 being infected with HSV1, it is incredibly common and just a single exposure to the virus can lead to infection."
Stage 3 -- Recurrence: When people encounter certain stresses (also termed triggers), emotional or physical, the virus may reactivate and cause new sores and symptoms. The following factors may contribute to or trigger recurrence: stress, illness, ultraviolet light (UV rays including sunshine), fever, fatigue, hormonal changes (for example, menstruation), immune depression, and trauma to a site or a nerve region where previous HSV infection occurred.