According to Indian folklore, herpes zoster — a blistering skin rash in a limited area — is caused by a gecko peeing on the skin. The various remedies suggested include poultices made from powdered bricks. Since most people recover even without treatment, almost any remedy could mistakenly be considered the cure.
Commonly called shingles (from the Latin singula for belt since it usually impacts the trunk, that is, the chest and abdomen), herpes zoster is caused by the varicella-zoster virus, which also causes chickenpox. After a bout of chickenpox, the virus can remain dormant in nerve tissue, sometimes for decades. If immunity declines, it can reactivate and travel along a nerve to the skin, causing shingles.
The risk of this happening increases with age, particularly after 50. Diabetes, certain cancers, chemotherapy and medicines that suppress the immune system also increase the likelihood of an attack.
There is no rash visible in the first few days but a person may feel fatigued, have low-grade fever, headache and body aches. There will also be pain, burning, tingling or itching in a particular area. During this confusing period, lasting one to five days, the symptoms could be diagnosed as some other disease.
Depending on its location, the pain may resemble that of kidney stones, gallstones, a heart problem, muscle spasm or an injury. In case of chest pain, go see a doctor even if you suspect that it is shingles.
Once the red rash appears, it is followed by clusters of fluid-filled blisters. These are usually limited to an area of skin supplied by a particular nerve. The rash typically forms only on one side of the body. The chest and abdomen are most commonly impacted, although the face and other areas can also be affected.
The blisters are both painful and intensely itchy. The fluid inside may become cloudy but this does not necessarily indicate bacterial infection. You must avoid scratching because that could lead to a secondary bacterial infection. If there is redness, swelling or pus, see a doctor immediately. Otherwise, the rash dries and crusts over. It usually heals completely in two to four weeks.
Diagnosis is based on the appearance of the rash and its distribution. Laboratory tests are not usually necessary. However, if diagnosis is uncertain, material from a blister can be tested.
You will not get shingles from exposure to a patient but if you have not had chickenpox — or been vaccinated against it — you could contract chickenpox.
Until all lesions have crusted, keep the rash covered. Wash hands regularly and avoid contact with susceptible pregnant women, newborns and people with weakened immunity.
Antiviral medicines such as acyclovir, valacyclovir or famciclovir work best when started promptly, ideally within 72 hours of the rash appearing. They help shorten the illness and also reduce its severity.
A rash on the forehead, eyelid or nose, or any eye pain, redness or visual disturbance requires urgent assessment because shingles can threaten sight. Rarely, particularly in people with severely weakened immunity, the infection becomes widespread or affects the brain (encephalitis).
Most people recover, but some develop post-herpetic neuralgia, a nerve pain that persists after the rash has healed, sometimes for months or years. It may feel like burning, stabbing or electric shocks, and even light clothing touching the skin can be painful.
Treatment must be tailored to the individual. Medicines used for nerve pain include gabapentin, pregabalin and certain antidepressants. Lignocaine patches or capsaicin preparations may help select patients once the skin has healed. These require medical guidance, especially in older adults.
Shingles can recur. Having one attack does not provide lifelong protection.
Fortunately, vaccination can substantially reduce the risk of shingles. A recombinant, non-live vaccine available in India for adults aged 50 and above is given as two intramuscular injections, usually two to six months apart.
Younger adults (19 years or older) with weakened immunity should discuss eligibility with their doctor. US recommendations include immunocompromised adults aged 19 and above. People who have already had shingles may also benefit from vaccination. Called Shingrix, the shot can be administered alongside other adult vaccines.
Vaccination should be postponed during an active shingles episode or any other significant acute illness. It is generally deferred during pregnancy but not during breastfeeding. Avoid taking a shot if you have had a severe allergic reaction to a previous dose or a vaccine component. Common side effects include pain, redness or swelling at the injection site, fatigue, muscle aches, headache, fever, chills and stomach upset. These usually settle within two or three days. Severe allergic reactions are rare.
Early recognition, prompt treatment and vaccination can greatly reduce the burden of herpes zoster.
The writer has a family practice at Vellore and is the author of Staying Healthy in Modern India. If you have questions on health issues, write to yourhealthgm@yahoo.co.in