Herpes simplex

A common viral infection, characterized by small, fluid-filled blisters. Herpes simplex infections are contagious and usually spread by direct contact. The virus has 2 forms, HSV1 (herpes simplex virus, type 1) and HSV2 (herpes simplex virus, type 2). Most people are infected with HSV1 at some point in their lives, usually during childhood. The initial infection may be symptomless, or may cause a flu-like illness with mouth ulcers. Thereafter, the virus remains dormant in nerve cells in the facial area. In many people, the virus is periodically reactivated, causing cold sores. Rarely, the virus infects the fingers, causing a painful eruption called a herpetic whitlow. HSV1 may produce eczema herpeticum (an extensive rash of skin blisters) in a person with a preexisting skin disorder, such as eczema. Eczema herpeticum may require hospital admission. If the virus gets into an eye, it may cause conjunctivitis or a corneal ulcer. Rarely, HSV1 spreads to the brain, leading to encephalitis. The virus may cause a potentially fatal generalized infection in a person with an immunodeficiency disorder or in someone taking immunosuppressant drugs. HSV2 is the usual cause of sexually transmitted genital herpes (see herpes, genital). Treatment of herpes simplex depends on its type, site, and severity. Antiviral drugs, such as aciclovir, may be helpful, particularly if used early in an infection.


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