Complications of Shingles (Herpes Zoster).The pain and discomfort of the active herpes zoster infection.Effects on Face and Ears.The following are ri

Pain. The pain and discomfort of the active herpes zoster infection is the primary symptom and complication of herpes zoster. The pain usually takes one of these forms:

Continuous burning or aching pain
Periodic piercing pain
Spasm similar to electric shock
Such experiences may also be more intense than even normal responses, defined in the following ways:

Allodynia is pain caused by factors, such as a light touch of clothing or a cold wind, which occurs from very little stimulation.
Hyperalgesia is a more intense painful response to a normally painful experience.
The pain tends to be more severe at night. Temperature changes can also affect pain. The pain may extend beyond the areas of the initial zoster attack. In most cases, it does not affect daily life. Rarely, however, the pain of herpes zoster affects sleep, mood, work, and overall quality of life. This can lead to fatigue, loss of appetite, depression, social withdrawal, and impaired daily functioning.

Itching. Many patients report itching (postherpetic itch) as the primary symptom, rather than pain. In rare cases, it can be disabling.

Postherpetic Neuralgia (PHN). Postherpetic neuralgia (PHN) is pain that persists for longer than a month after the onset of herpes. It is the most common severe complication of shingles. It is not clear why PHN occurs. Some theories for its development are:

The herpes zoster virus appears to produce persistent inflammation in the spinal cord that causes long-term damage, including nerve scarring.
Nerves that are injured in the initial attack may heal abnormally and provoke an exaggerated response in the brain that produces intense sensitivity or pain.
In people with herpes zoster, the risk of developing PHN ranges from 10 - 70%. In general, however, the risk is likely to be in the lower range. People with impaired immune systems do not seem to be at any higher risk for persistent PHN than those with normal immune systems.

The following are risk factors for PHN:

Age. PHN affects about 25% of herpes zoster patients over 60 years old. The older a person is, the longer PHN is likely to last. It rarely occurs in people under age 50.
Gender. Some studies suggest that women may be at slightly higher risk for PHN than men.
Severe or Complicated Shingles. People who had prodromal symptoms or a severe attack (numerous blisters and severe pain) during the initial shingles episode are also at high risk for PHN. The rate is also higher in people whose eyes have been affected by zoster.
In most cases, PHN resolves within 3 months. Some doctors define persistent pain after a herpes zoster attack as subacute herpetic neuralgia if it lasts between 1 - 3 months and as PHN only if it lasts beyond 3 months. Studies report that only about 10% of patients experience pain after a year. Unfortunately, when PHN is severe and treatments have not been very effective, the persistent pain and abnormal sensations can be profoundly frustrating and depressing for patients.

Secondary Infection in the Blisters. If the blistered area is not kept clean and free from irritation, it may become infected with group A Streptococcus or Staphylococcus bacteria. If the infection is severe, scarring can occur.

Guillain-Barre Syndrome. Guillain-Barre syndrome is caused by inflammation of the nerves and has been associated with a number of viruses, including herpes zoster. The arms and legs become weak, painful, and, sometimes, even paralyzed. The trunk and face may be affected. Symptoms vary from mild to severe enough to require hospitalization. The disorder resolves in a few weeks to months. Other herpes viruses (cytomegalovirus and Epstein-Barr), or bacteria (Campylobacter) may have a stronger association with this syndrome than herpes zoster.

Effects on Face and Ears.

Ramsay Hunt Syndrome. Ramsay Hunt syndrome occurs when herpes zoster causes facial paralysis and rash on the ear (herpes zoster oticus) or in the mouth. Symptoms include severe ear pain and hearing loss, ringing in the ear, loss of taste, nausea, vomiting, and dizziness. Ramsay Hunt syndrome may also cause a mild inflammation in the brain. The dizziness may last for a few days, or even weeks, but usually resolves. Severity of hearing loss varies from partial to total; however, this too usually always goes away. Facial paralysis, on the other hand, may be permanent.
Bell's Palsy. Bell's palsy is partial paralysis of the face. There is some indication that this syndrome may suggest a reactivation of herpes zoster, even if no rash appears.
Sometimes, it is difficult to distinguish between Bell's palsy and Ramsay Hunt syndrome, particularly in the early stages. In general, Ramsay Hunt syndrome tends to be more severe than Bell's palsy.
Effects on the Brain. Inflammation of the membrane around the brain (meningitis) or in the brain itself (encephalitis) is a rare complication in people with herpes zoster. The encephalitis is generally mild and resolves in a short period. In rare cases, particularly in patients with impaired immune systems, it can be severe and even life threatening.