Herpes zoster

Herpes zoster, colloquially known as shingles, is the reactivation (from the nerve cell body in the sensory ganglion of a segment of the spinal cord) of varicella zoster virus (VZV, primary infection of which leads to chickenpox), one of the Herpesviridae group, leading to a crop of painful blisters over the area of a dermatome. In Italy and in Malta, it is sometimes referred to as "St. Anthony's fire", although that name usually refers to ergotism. Shingles, or herpes zoster, is a neurological disease, affecting the nervous system with or without the appearance of a rash on the skin.

Treatment is generally with antiviral drugs such as acyclovir (Zovirax), or prodrugs such as famciclovir (Famvir), or valacyclovir (Valtrex). For the antiviral drugs to be most effective, patients should begin taking them as soon as possible after the appearance of the rash, within 12 to 72 hours for maximum efficacy.