Posted on 11 November 2015
Shingles is a viral infection that results in a painful rash. We put your answers some frequently asked questions to Dr Lawrence Archer, a GP and supporting doctor at Mediclinic Newcastle.
What is shingles and what causes it?
Shingles is a reactivation or relapse of infection with the herpes zoster virus (chickenpox). This virus lies dormant in the dorsal ganglion of the cranial nerves or spinal nerves for many years until the host’s immunity wanes, then it can multiply along the nerve root and cause an extremely painful condition by damaging the predominately sensory component of the nerve, resulting in vesicles (blisters) in the distribution of the nerve. In a healthy individual there may be a few blisters along the nerve, while in a severely immune-compromised person such as a terminal Aids patient, there could be a full-thickness destruction of skin and even spillover to full-blown chickenpox.
How is shingles treated?
Antiviral drugs are prescribed for the virus, such as acyclovir 800mg five times a day for seven days, started as soon as possible, preferably within 48 hours of the onset of the rash. Also indicated are analgesics, calamine lotion for rash and drugs used for neuropathic pain. Cortisone should be avoided except in special circumstances. If the eye is involved, as in an infection of the ophthalmic branch of trigeminal cranial nerve, an ophthalmologist should be consulted. Passive immunity using immunoglobulins could be considered for severely immune-compromised patients.
How long does shingles usually last?
Several weeks to months, depending on the immune status of the patient.
How can you avoid contracting shingles?
Boost the immune system, specifically against herpes zoster infection. Vaccinate against chickenpox, or against being exposed to a wild strain of chickenpox. The NHS of England recommends giving elderly people 10-yearly vaccinations to avoid shingles.
Boost your immunity with a vaccination and avoid exposure to children with chicken pox. You can’t contract shingles from someone who has chickenpox, but the blisters of shingles contain the virus, which can pass on chickenpox to non-immune people.
Does shingles recur?
Generally not – but it can, especially if the immune system is compromised or immunity wanes.
Is it contagious?
The watery blisters contain an active virus with the potential of causing chickenpox. Once the blisters have crusted they are not contagious any more. Incubation of the virus is 14 to 21 days.
What other complications can occur?
In severe cases, permanent nerve damage can result in a condition known as post-herpetic neuralgic syndrome. This results in abnormal pain in the area involved – sometimes for life. The sensory wiring essentially gets cross-wired, resulting in the touch sensation becoming painful. In severely immune-compromised patients, the virus can spills over and cause tissue destruction and scarring of the skin. Blindness can also result from cornea damage.
Who is at greatest risk for shingles?
Immune-compromised people are at greater risk. It’s therefore policy to test for the HIV virus, as this may be the first sign. People over the age of 50 are also at greater risk.