[Postherpetic neuralgia].

Following chicken pox infection, varicella-zoster virus stays as a latent infection in sensory root ganglia. After many years, the reactivation of this latent virus in sensory ganglia causes "herpes zoster". Herpes zoster (shingles) is an unilateral, dermatomal, localised, painful, vesicular, and contagious skin infection. In elderly and immunocompromised patients, shingles can cause complications such as postherpetic neuralgia (PHN) and direct central nervous system invasion. Early intervention with antiviral treatment, analgesic therapy and antidepressant therapy may reduce the risk of these complications. The treatment of PHN is same as for other neuropathic pain syndromes. The clinical importance of PHN is due to the severity and chronicity of pain which is usually not responsive to many treatments, and quality of life may be adversely affected by PHN.