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Shingles Complications
Postherpetic Neuralgia

Sometimes, particularly in older people, shingles pain persists long after the rash has healed. This postherpetic neuralgia can be mild or severe - the most severe cases can lead to insomnia, weight loss, depression, and disability. Postherpetic neuralgia is not directly life-threatening. About a dozen medications in four categories have been shown in clinical trials to provide some pain relief. These include:

Tricyclic antidepressants (TCAs): TCAs are often the first type of drug given to patients suffering from postherpetic neuralgia. The TCA amitryptiline was commonly prescribed in the past, but although effective, it has a high rate of side effects. Desipramine and nortriptyline have fewer side effects and are therefore better choices for older adults, the most likely group to have postherpetic neuralgia.

Common side effects of TCAs include dry eyes and mouth, constipation, and grogginess. People with heart arrhythmias, previous heart attacks, or narrow angle glaucoma should usually use a different class of drugs.

Anticonvulsants: Some drugs that reduce seizures can also treat postherpetic neuralgia because seizures and pain both involve abnormally increased firing of nerve cells. An antiseizure medication, carbamazepine, is effective for postherpetic neuralgia but has rare, potentially dangerous side effects so a newer anticonvulsant, gabapentin, is far more often prescribed. Side effects of the drug include drowsiness or confusion, dizziness, and sometimes ankle swelling.

Opioids: Opioids are strong pain medications used for all types of pain. They include oxycodone, morphine, tramadol, and methadone. Opioids can have side effects - including drowsiness, mental dulling, and constipation - and can be addictive, so their use must be monitored carefully in those with a history of addiction.

Topical local anesthetics: Local anesthetics applied directly to the skin of the painful area affected by postherpetic neuralgia are also effective. Lidocaine, the most commonly prescribed, is available in cream, gel, or spray form. It is also available in a patch that has been approved by the Food and Drug Administration for use specifically in postherpetic neuralgia. With topical local anesthetics, the drug stays in the skin and therefore does not cause problems such as drowsiness or constipation. Capsaicin cream may be somewhat effective and is available over the counter, but most people find that it causes severe burning pain during application.

Postherpetic itch

The itch that sometimes occurs during or after shingles can be quite severe and painful. Clinical experience suggests that postherpetic itch is harder to treat than postherpetic neuralgia. Topical local anesthetics (which numb the skin) provide substantial relief to some patients. Since postherpetic itch typically develops in skin that has severe sensory loss, it is particularly important to avoid scratching. Scratching numb skin too long or too hard can cause injury.

Other Complications

People with ophthalmic shingles -- lesions in or around the eye and forehead -- can suffer painful eye infections, and in some cases immediate or delayed vision loss. People with shingles in or near the eye should see an ophthalmologist immediately. Shingles infections within or near the ear (Ramsay-Hunt syndrome) can cause hearing or balance problems as well as weakness of the muscles on the affected side of the face. In rare cases, shingles can spread into the brain or spinal cord and cause serious complications such as stroke or meningitis (an infection of the membranes outside the brain and spinal cord). People with shingles need to seek immediate medical evaluation if they notice neurological symptoms outside the region of the primary shingles attack. People who are immunosuppressed, whether from diseases such as HIV or medications, have an increased risk of serious complications from shingles. Most commonly, they get shingles that spreads to involve more parts of the body, or shingles rashes that persist for long periods or return frequently. Many such patients are helped by taking antiviral medications on a continuous basis.

Pregnancy

Many mothers-to-be are concerned about any infection contracted during pregnancy, and rightly so because some infections can be transmitted across the mother's bloodstream to the fetus or can be acquired by the baby during the birth process. VZV infection during pregnancy poses some risk to the unborn child, depending upon the stage of pregnancy. During the first 30 weeks, maternal chickenpox may, in some cases, lead to congenital malformations. Such cases are rare and experts differ in their opinions on how great the risk is. Most experts agree that shingles in a pregnant woman, a rare event, is even less likely to cause harm to the unborn child.

If a pregnant woman gets chickenpox between 21 to 5 days before giving birth, her newborn can have chickenpox at birth or develop it within a few days. But the time lapse between the start of the mother's illness and the birth of the baby generally allows the mother's immune system to react and produce antibodies to fight the virus. These antibodies can be transmitted to the unborn child and thus help fight the infection. Still, a small percent of the babies exposed to chickenpox in the 21 to 5 days before birth develop shingles in the first 5 years of life because the newborn's immune system is not yet fully functional and capable of keeping the virus latent.

What if the mother contracts chickenpox at the time of birth? In that case the mother's immune system has not had a chance to mobilize its forces. And although some of the mother's antibodies will be transmitted to the newborn via the placenta, the newborn will have little ability to fight off the attack because its immune system is immature. If these babies develop chickenpox as a result, it can be fatal. They are given zoster immune globulin, a preparation made from the antibody-rich blood of adults who have recently recovered from chickenpox or shingles, to lessen the severity of their chickenpox.

 

Reference:

National Institute of Neurological Disorders and Stroke, USA.