It is estimated that nearly 1 in 3 people will get shingles. If you have had chickenpox and are 50 years or older, you are at risk. After a person has had chickenpox, the virus (varicella-zoster) remains dormant in the body. It basically goes to sleep in the nerves where it is usually held in check by a strong immune system. Unfortunately, as we age, the immune system tends to weaken which can allow the dormant virus to awaken. If you live to 85 you have a one in two chance of getting shingles.
The immune system can also be suppressed by emotional trauma, a serious illness or certain medications such as steroids or chemotherapy.
The first sign of shingles is usually a tingling or burning sensation on one side of your body or face. Common areas are the face, and around the lower ribs, but it can also occur down an arm or leg. Within days, tiny red spots will appear - usually in a cluster, and then quickly evolve into a group of painful blisters which can pop or get crusty. Unless you are immunocompromised, the rash almost never crosses the midline of your body. It is unilateral (one sided) because it is localized to one nerve root. After a week or two the blisters will start to heal and form scabs.
If you get the rash around your eye it is important to see your optometrist or eye specialist to have your eye checked as you could develop conjunctivitis, keratitis, uveitis or problems with your optic nerve resulting in chronic ocular inflammation, loss of vision and debilitating pain. If the rash involves the ear it can result in hearing loss and vertigo.
The shingles vaccine (Zostavax), only halves your chance of getting shingles. It contains a weakened chickenpox virus, called the ‘varicella-zoster’ virus. Having this vaccine primes your immune system to defend against the disease.
In a recent study published in the New England Journal of Medicine, Sept 2016, an experimental vaccine called HZ/su (dubbed Shingrix) was shown to protect about 90% of adults over 70 with the effects lasting for up to four years. This is far better than the performance of Zostavax but it is not yet available to the public.
Up to 15% of people with shingles will develop severe pain called post-herpetic neuralgia that follows after the infection has run its course. The pain has been described as excruciating, and can continue for months or even years, especially in older people. The chance of getting this unfortunate syndrome increases the older the you are.
While the current vaccine is more than 95% effective in preventing severe infections, the main aim of the vaccine is to limit severity and duration of pain, shorten the duration of a shingles episode and reduce complications. The effects last about 3 years.
If you do get shingles, antiviral drugs may reduce the severity and duration of shingles but they do not prevent the dreaded post-herpetic neuralgia and there is no benefit if they are started more than 72 hours after the start of the rash.