herpes

n.

inflammation of the skin or mucous membranes that is caused by herpesviruses and characterized by collections of small blisters. There are two types of herpes simplex virus (HSV): type I causes the common cold sore, usually present on or around the lips; type II is mainly associated with genital herpes and is sexually transmitted. However, types I and II can both cause either genital herpes or cold sores, depending on the site of initial infection. HSV blisters are contagious through skin-to-skin contact and are recurrent in some people. HSV can also affect the conjunctiva (see also dendritic ulcer).

Herpes zoster (shingles) is caused by the varicella-zoster virus, which also causes chickenpox. Following an attack of chickenpox, the virus lies dormant in the dorsal root ganglia of the spinal cord. Later, under one of a number of influences, the virus migrates down the sensory nerve to affect one or more dermatomes on the skin in a band, causing the characteristic shingles rash. One side of the face or an eye (ophthalmic zoster) may be involved. Shingles may be chronically painful (post-herpetic neuralgia), especially in the elderly. See also Ramsay Hunt syndrome.

Treatment of all forms of herpes is with an appropriate preparation of aciclovir or related antiviral drugs; shingles may require potent analgesics.