<unk>  is a viral disease caused by<unk>  viruses. Infection of the genitals is commonly known as<unk>  and predominantly occurs following sexual transmission of the type 2 strain of the virus <unk> V-2). Oral<unk> , colloquially called cold sores, is usually caused by the type 1 strain of<unk>  virus <unk> V-1).  Both viruses cause periods of active disease—presenting as painful blisters containing infectious virus particles—that lasts 2-21 days and is followed by remission when the sores disappear. Most cases of genital<unk>  are asymptomatic, although viral shedding may still occur.<unk> V-1 and<unk> V-2 are transmitted by direct contact with a sore or body fluid of an infected individual.  After initial infection, these viruses move to sensory nerves, where they reside as life-long, latent viruses. The viruses lie dormant in trigeminal ganglia that provide sensation to the lips, lower mouth, and neck, or in lumbrosacral, which supply sensation to the genitals, perineum, and upper legs.  Occasionally, these viruses reactivate and return to the area of skin infected during the primary infection.  Triggers for recurrences are uncertain but may include sunburn, ultraviolet light, wind, trauma, surgery, and stress. Over time, episodes of active disease reduce and the frequency of recurrences is regulated by specific immunity developed against the virus.
Herpes simplex
Herpes labialis
Linea negra
Herpes gladiatorum
Smallpox
Cowpox
Lichen aureus
Tinea faciei