Description

• Usually seen as an exanthem consisting of painful vesicles that occur often in clusters on skin, cornea, or mucous membranes
• Local skin lesions primarily located in oral and genital regions:
  • Herpes simplex virus (HSV)-1 primarily associated with blisters on lips, in mouth, face, eyes
  • HSV-2 is primary source of genital herpes, although cross-reactivity is common (with HSV-1 being a cause of genital sores as well due to oral–genital contact).
• Viral disease with a wide range of sequelae. Complexity and variation of presentation is dependent on if it is a disseminated infection, age and immune status of host, and whether the rash outbreak is primary or recurrence.
• HSV can lead to meningitis/encephalitis and pneumonia among its systemic manifestations.
• Amount of viral shedding varies, but is greatest in the first/primary infection and lessens with subsequent infections.

Epidemiology

• Predominant age: Affects all ages; however, most HSV-1 is acquired in childhood, and most HSV-2 is acquired in young–middle adulthood.
• Predominant sex: Male = Female

• 29.2/100,000 office visits per year for herpes simplex-related codes
• HSV is never eliminated from the body, but stays dormant and can reactivate, causing symptoms.

• Widespread; 0.65–25% of adults may be excreting HSV-1 or HSV-2 at any given time, many of whom are unaware of this infection status.
• Prevalence of antibodies to HSV-1 is 90% by adulthood in the general population, and 30% of adults have antibodies to HSV-2.

Risk Factors

• Immunocompromised host, both acutely and chronic:
  • During presence of other illness or stress
  • Chemotherapy, malignancy/chronic disease states, such as diabetes or AIDS, older age
• Atopic eczema, especially in children
• Prior HSV infection
• Sexual intercourse with infected person (condoms help minimize HSV transmission, but location of lesions outside condom-protected areas limit their effectiveness)
• Occupational exposure:
  • Dental professionals at higher risk for HSV-1 and resulting herpetic whitlow

• Neonatal herpes simplex: Primary perinatal infection is life threatening and usually acquired by vaginal birth via infected mother; fetal risk and neonatal risk are greater in mothers with primary genital herpes infection because shedding is more prolonged and the inoculum is greater; incubation from 5–7 days usually (rarely 4 weeks); cutaneous, mucous membrane, or ocular signs in only 70%.

General Prevention

• Those with active disease should avoid direct contact with immunocompromised people, the elderly, and newborns.
• Wash hands often. Wash all linens with hot water immediately after lesions resolve.
• Kissing, sharing beverages from the same container and sharing food utensils/toothbrushes can transmit HSV.
• Genital herpes: Avoid sexual contact while disease is active (recognizing herpes simplex is transmitted even when disease appears to be inactive), discuss condom benefits and limits, consider antiviral therapy to reduce viral shedding, and reinforce benefits of mutually monogamous sexual relations.
• Topical microbicides (gels) are showing promise (but not yet commercially available) to prevent acquisition of HSV-2 (1)[A].

Etiology

HSV, a DNA virus of 2 major types: HSV-1 and HSV-2. Most often, HSV-1 is associated with oral lesions, and HSV-2 with genital lesions, but reverse also occurs.

Commonly Associated Conditions

• Erythema multiforme: 50% of associated cases are caused by HSV-1 or -2.
• All severe, unusual locations or treatment-resistant HSV cases should be screened for HIV.