Shingles is a viral infection, the first symptom of which is usually a tingling, sharp, burning pain under the skin, followed after 1-3 days by a red rash and blisters.
Shingles is caused by the same virus as chickenpox (varicella zoster). After a bout of chickenpox the virus lies latent in the nerve cells near the spinal cord. It remains there for life and can be reactivated at a later stage as shingles. Anyone who has had chickenpox can go on to develop shingles.
Signs and symptoms
Shingles, also known as herpes zoster, can occur at any age but usually occurs in adults over the age of 60 years. Shingles affects males and females equally.
Groups at an increased risk of developing shingles include people whose immune systems have been impaired due to ill health, medications or diseases that lower the immunity.
The initial tingling, sharp, burning pain under the skin can occur anywhere on the body but usually affects the face, upper abdomen or back and almost always occurs on one side of the body only. The pain can be mild or it can be quite severe. In general, the older the person is, the more severe the pain is likely to be. It can be accompanied by other symptoms including:
- A feeling of being generally unwell
- Mild chills and fever
- Headache
- An upset stomach
- Enlarged lymph nodes.
After 1-3 days a red rash appears over the painful area of skin followed quickly by the development of small, fluid filled blisters. The rash can be quite itchy. Within a few days of appearing the blisters dry and crust over. It is possible for the blisters to cause mild scarring.
Because shingles affects the nerve cells it is common for the rash to appear as a band across the body or down the leg along the path of a nerve. Occasionally the rash does not eventuate after the initial pain has developed. The pain and other symptoms of shingles gradually resolve as the skin rash and blisters disappear. Full recovery from the condition usually occurs within 2-3 weeks, or up to 4 weeks in older adults.
Causes
The reason why the chickenpox virus reactivates as shingles is not fully understood. It is thought that the following factors influence the development of shingles:
- Emotional stress
- Lowered immunity eg: due to immuno-suppressant medications or chemotherapy
- A recent illness or major surgery
- Age.
However, in most people there is no identifiable cause for shingles occurring.
Diagnosis
A doctor is usually able to make a diagnosis of shingles based on its characteristic symptoms. A full medical history will be taken and the doctor may take a sample of the fluid within the blister so that it can be tested in a laboratory for presence of the shingles virus.
Treatment
As shingles is caused by a virus and cannot be cured with antibiotics, treatment focuses on relieving symptoms. Getting adequate rest is an important factor in the treatment of shingles. Other treatment may include:
- Pain relief medications such as paracetamol
- Cool compresses applied to the affected area
- Lotions and creams may be prescribed for the rash
- Antiviral medications such as acyclovir may be prescribed. These do not destroy the virus but can help to reduce the duration of the symptoms
- Steroids may be prescribed if the rash and pain is severe
- Antibiotics may be required if the skin rash becomes infected
- Acupuncture can also be effective in relieving symptoms in some cases.
If the shingles rash has affected the eyes, treatment by an ophthalmologist (eye specialist) may be required to prevent damage to the cornea (the transparent part of the eyeball which covers the iris and pupil).
Transmission
The virus that causes shingles (varicella zoster) is present in the fluid within the blisters of people suffering from shingles. Transmission of this virus mainly occurs through direct or indirect contact with the fluid in the blisters. Rarely, the virus can be transmitted in droplets of saliva from the nose and mouth.
A person with shingles is contagious from when the blisters first develop until after all of the blisters have crusted over. If the virus is transmitted from a person who has shingles to a person who has not had chickenpox, that person will develop chickenpox, not shingles.
Complications
The most common complication of shingles is a condition called post-herpetic neuralgia. This condition is characterised by persistent pain at the site of the shingles rash that lasts for more than one month. Anti-seizure and anti-depressant medications are sometimes used to treat the pain caused by post-herpetic neuralgia. Other less common complications of shingles include:
- Bacterial skin infections
- Damage to the unborn foetus if the mother develops shingles in the early months of pregnancy, though this is very rare
- Damage to the eye if shingles affecting the eye is left untreated. In rare cases, blindness can occur
- Ramsay Hunt's syndrome caused by facial shingles. This condition can cause ear pain, facial paralysis, loss of taste and hearing.
Most complications of shingles are very rare, but it is still important to consult a doctor as soon as shingles is suspected so that an accurate diagnosis and appropriate treatment can be given. This is especially important for those people with a weakened immune system.
Prevention / vaccination
A shingles vaccine is available in New Zealand called zostavax, that can be given to people 50 years and older. The vaccine reduces the risk of shingles developing and may help to reduce the severity and duration of shingles if it does occur.
Further information
If you believe you may have shingles or you want to know if the shingles vaccine is suitable for you, contact your GP or practice nurse, or call Healthline on 0800 611 116 (24 hours a day, 7 days a week).
References
Doermann, D. J., Frey, R. J. (2006) Shingles. The Gale Encyclopedia of Medicine. Third Edition. Jacqueline L. Longe, Editor. Farmington Hills, MI: Thomson Gale.
DermNet NZ (2011) Shingles. New Zealand Dermatological Society.
http://dermnetnz.org/viral/herpes-zoster.html
Glanze, W.D., Anderson, K.N. & Anderson, L.E. (Eds.) (2006) Mosby’s medical, nursing and allied health dictionary. (6th ed.) St.Louis: Mosby – Year Book Inc.
Last Reviewed – 26 November 2012