Herpes Zoster (Shingles)
Herpes zoster (or simply zoster), commonly known as shingles and also known as zona, is a viral disease characterized by a painful skin rash with blisters in a limited area on one side of the body, often in a stripe. The initial infection with varicella zoster virus (VZV) causes the acute (short-lived) illness chickenpox which generally occurs in children and young people.
Postherpetic Neuralgia
Postherpetic neuralgia (PHN) is a nerve pain due to damage caused by the varicella zoster virus. Typically, the neuralgia is confined to a dermatomic area of the skin and follows an outbreak of herpes zoster (HZ, commonly known as shingles) in that same dermatomic area. The neuralgia typically begins when the HZ vesicles have crusted over and begun to heal, but it can begin in the absence of HZ, in which case zoster sine herpete is presumed (see Herpes zoster).