Herpes simplex virus (HSV) is the pathogen that causes peri-stomal vesicular lesions, commonly known as ‘cold sores.’1 The word herpes originates from the Greek word meaning “to creep or to crawl.” While HSV-1 is largely responsible for oral infections and HSV-2 is associated with genital herpes, oral infection with HSV-2 is not uncommon. In the US, an estimated 500,000 primary infections occur yearly, while approximately 50% of the population carries the virus.1,2 The incubation period ranges from 1-26 days following exposure (median 6-8 days).3 The virus can cause infection in other parts of the body, including the lung, liver, eye, central nervous system; however, these are typically only seen in immunocompromised patients.
Inoculation requires direct contact with the virus, allowing it to penetrate the dermis and travel to local nerves. Infection is much more common when lesions are present, as viral titers are 100 to 1000 times higher.3 However, patients with infection can be asymptomatic. Only 20-25% of HSV-1 antibody-positive individuals and 10-20% of HSV-2 antibody-positive individuals have a history of oral or genital infection.4,5 Asymptomatic viral shedding can occur, leading to transmission of disease from those without active symptoms.3
After resolution of the primary infection, the virus lays dormant in a nerve ganglion. Reactivation can occur and has numerous risk factors, including stress and immune suppression. Approximately 60% of people in the US are seropositive for HSV-1 antibodies.6