herpes zoster (shingles)

a condition characterized by painful blisters that typically appear in a dermatomal (linear) distribution on the skin following nerve pathways; blisters generally dry and scab leaving minor scarring. Shingles is caused by reactivation of a previous infection with the varicella-zoster virus (VZV) that initially causes chickenpox; VZV lies dormant in the nerves and reactivates when immune defenses are weakened. Shingles outbreaks may recur more frequently and VZV may become disseminated in people with HIV disease. Disseminated herpes zoster resembles chicken pox, with a rash, fever and possibly pneumonia; herpes zoster may also lead to ocular and neurological complications.