About 95% of the adults in the UK have had chicken pox and are therefore at risk of developing shingles (Herpes Zoster), a reactivation of the chicken pox virus. The chicken pox virus (Varicella Zoster Virus, VZV or Herpes Varicella when causing chicken pox) is not completely removed from the body after chicken pox gets better; it remains dormant (or latent) in sensory nerves. Shingles occurs when this virus reactivates from the nerve to cause symptoms in the skin or other site supplied by the specific nerve.
- Age > 70 years
- Emotional stress
- Decreased immunity e.g. chemotherapy, immunosuppressants, HIV, etc.
How is shingles diagnosed and what are the clinical features?
Shingles is normally diagnosed clinically based on the history and appearance of the skin lesions. Patients usually have a history of chicken pox, although chicken pox can be asymptomatic and still lead to shingles in the future! The most common sites affected are the thorax and abdomen followed by the face and eyes although any part of the body can potentially be affected.
Shingles normally starts as itching, burning or numbness in the skin supplied by the affected nerve associated with malaise, headache and occasionally a high fever. The skin affected is dermatomal, i.e. the pain is very specifically localised to one side of the body and doesn’t cross the midline. On the face the pain is specifically located to a particular branch of the trigeminal nerve; mandibular, maxillary or ophthalmic (see picture below). A few days after the pain or discomfort starts red blotches and then blisters appear in the same area of skin. This is usually associated with constant moderate to severe burning pain with sharp stabbing episodes. Symptoms usually persist for 2-4 weeks although the rash can lead to permanent scarring.
How is shingles treated?
There are three main aspects to the treatment of shingles; analgesia, antivirals and prevention of secondary infections.
Shingles is very painful! Patients should be advised to take regular analgesics such as paracetamol, ibuprofen, codeine or even a combination of all three if necessary.
Aciclovir is the normal antiviral used to treat infections caused by VZV. The use of Aciclovir in shingles can reduce the severity of symptoms, shorten the duration of illness and decrease the risk of complications. It is a pro-drug, activated by the virus itself, and it is more effective the earlier it is given in the illness. Ideally Aciclovir, 800mg five times a day for 7 days, should be started within 72 hours of the onset of illness but it can still be of benefit if started within a week of symptoms developing.
Aciclovir is normally given to patients who fulfil one of the following indications:
- Over 50 years old
- Ophthalmic shingles
- Immunocompromised due to drugs or other conditions e.g. HIV
- Moderate to severe pain or rash
Secondary infections can be prevented by covering the lesions loosely with a non-adherent dressing and keeping them clean with gentle washing. Topical antibiotics should not be applied (see the topical topic blog)!
Can I catch shingles?
You cannot catch shingles, but you can catch chicken pox. Remember shingles is the reactivation of the chicken pox virus. You cannot develop shingles unless you have had chicken pox first; in fact shingles is actually proof of past infection and immunity to the chicken pox virus.
However, it is possible to catch chicken pox from shingles! The blister fluid is full of the virus and if someone who has not had chicken pox comes into contact with the blisters, fluid or even clothing/bedding which has been in contact with the fluid, then they can potentially develop chicken pox. Patients with shingles should try to keep the affected area covered. This is not normally a problem when the shingles affects the thorax or abdomen, but is difficult when the face or head is affected.
Patients who work with people at risk of severe chicken pox should be advised to stay off work until there are no new lesions and the old blisters have dried and crusted over which can take 10-14 days. Those at risk of severe chicken pox include:
- Immunosuppressed e.g. transplant recipients, bone marrow suppression, chemotherapy, steroids, etc
- Pregnancy, where chicken pox can have up to 10% mortality
- Babies born to non-immune mothers and very premature babies <31 weeks gestation as neither will have any immunity from their mothers
What are the complications of shingles?
Most patients will only have 1 or 2 episodes of shingles during their lifetime.
1 in 5 patients will develop a complication of their shingles called post-herpetic neuralgia (PHN). This is severe pain which continues in the same area of skin affected by the shingles. PHN usually lasts 3-6 months although it can very rarely last indefinitely.
Other rare complications of shingles include:
- Meningitis and encephalitis
- Ramsay-Hunt Syndrome – the virus affects the facial nerve leading to paralysis of the muscles supplied by this nerve as well as loss of hearing on the affected side, vertigo and taste disturbance
Can shingles be prevented?
The only sure fire way of not getting shingles is to not get chicken pox, but since chicken pox as an adult can be much more serious than shingles this is not recommended.
It is currently recommended in the UK that 70 year olds are given the chicken pox vaccine in order to reduce the likelihood of them developing shingles and PHN. Essentially the vaccine gives the person’s immune system a boost in order to keep the virus under control. The vaccine reduces the risk of shingles by 51% and PHN by 67%. This may not sound like much, but given that there are about 10 million over 70 year olds in the UK this would equate to reducing the number of cases of shingles by about 1 million in this age group!
Okay, so why cover shingles this week? Well the patient concerned is me and I can tell you first hand that shingles is really very painful... yep, very painful indeed, and yep, I’m feeling a little sorry for myself... :-(
Here’s a useful summary: 7 Myths about Shingles