). Shingles Shingles Shingles is a painful skin rash caused by a viral infection that results from reactivation of the varicella-zoster virus, the virus that causes chickenpox. What causes the virus to reactive... read more is a painful rash of fluid-filled blisters that is caused by reactivation of the varicella-zoster virus Overview of Viral Infections A virus is composed of nucleic acid, either DNA or RNA, surrounded by a protein coat. It requires a living cell in which to multiply. A viral infection can lead to a spectrum of symptoms from... read more , the virus that causes chickenpox Chickenpox Chickenpox is a highly contagious viral infection with the varicella-zoster virus that causes a characteristic itchy rash, consisting of small, raised, blistered, or crusted spots. Chickenpox... read more 
. The varicella-zoster virus is a member of the herpesvirus Overview of Herpesvirus Infections Some common viral infections are caused by herpesviruses. Eight different herpesviruses infect people: Three herpesviruses— herpes simplex virus type 1, herpes simplex virus type 2, and varicella-zoster... read more family (herpesvirus type 3). Shingles is sometimes called herpes zoster. Some people who have had shingles continue to have pain long after the rash has gone away. Such pain is called postherpetic neuralgia, which means nerve pain after herpes.
Exactly why postherpetic neuralgia occurs is not well-understood.
Postherpetic neuralgia occurs most often in older people. As people age, the chance of developing postherpetic neuralgia increases.
Symptoms of Postherpetic Neuralgia
The pain of postherpetic neuralgia occurs in the area where the shingles rash occurred. The pain may be constant or intermittent. The pain may be severe and even incapacitating.
The pain may subside within several months but may persist for years.
Diagnosis of Postherpetic Neuralgia
A doctor's evaluation
If people who have had shingles continue to have pain in the area affected by shingles, they should see a doctor.
Postherpetic neuralgia diagnosis is usually based on symptoms and results of a physical examination in people who have had shingles.
Treatment of Postherpetic Neuralgia
Pain-relieving drugs or creams
Sometimes other drugs
Although a number of treatments for severe postherpetic neuralgia have been tried, no treatment is routinely successful.
Postherpetic neuralgia treatments may include
Certain antidepressants (such as amitriptyline)
Topical lidocaine ointment
Sometimes opioids
Botulinum toxin A injected into the affected area, which may reduce the pain
