What is shingles?
Herpes zoster, or shingles, is a very painful, suddenly appearing skin reaction accompanied by small blisters. It is caused by a reactivation of the chickenpox virus.
Chickenpox (varicella) is a viral infection that almost everyone goes through in childhood. During the infection (which affects the whole skin) the virus is cleared by the body’s defence system, but some of the virus manages to “hide” in nerve cells of the spinal cord, preferably nerve cells connected to the skin. The virus remains present in these cells throughout life without causing problems. In certain circumstances, however — especially when resistance falls — some of the virus can become active again. It then grows along the nerve pathways to the skin and there produces the painful skin lesion we call shingles.
What does shingles look like?
The first complaints are usually burning and pain in a particular area of skin — the area supplied by a specific nerve pathway from the spinal cord, called a “dermatome”. Shingles therefore almost always occurs in a clearly defined area of skin. On the trunk and face the lesions are typically one-sided. When the face or forehead is affected, there is often severe headache in the period before the skin lesions appear. The skin becomes red and, within a few hours to days, blisters filled with clear fluid develop, usually in small groups. After about 10 days the blisters dry up and the red rash gradually disappears, though new blisters can sometimes still appear during the drying process. Throughout this period there is a lot of pain in the skin.
Who can get it?
Because almost everyone has had a chickenpox infection at some point, in principle anyone can develop shingles. People aged 60 and over are most likely to get it; it is only very rarely seen in children. People with reduced resistance (such as those taking prednisone) have a greater chance of an attack, and patients with very low resistance can develop extensive, very severe infections that are no longer limited to one dermatome but can even cover the whole skin.
Shingles of the face
This form deserves extra attention. Shingles of the face is often accompanied by very severe (head) pain, and sometimes the facial muscles can be temporarily paralysed by the virus; in most patients this recovers completely. When the area around the eye is involved, inflammation inside the eye can develop that, if untreated, can in some cases lead to permanent damage. Shingles in the eye area should therefore always be assessed by an eye specialist, and it is also a good reason to start antiviral medicines.
How is shingles diagnosed?
It is usually not difficult for the doctor to recognise shingles. In case of doubt, a swab from a blister can be cultured to demonstrate the virus, though the result always takes a few days.
Pain
One of the biggest problems with shingles is pain. This can be particularly severe and can persist for up to six months after the shingles has disappeared. This “post-herpetic pain” is seen mainly in older patients and after shingles of the face. Good pain relief is therefore very important; one of the treatments that can be prescribed is capsaicin cream (“pepper cream”).
Is it contagious?
During a shingles attack, especially when blisters are present, the virus can be passed to people who have never had chickenpox — in practice mainly children. Because chickenpox can be dangerous for newborns and babies, people with active shingles should avoid contact with these children. Conversely, in older people, contact with children who have chickenpox can trigger shingles.
How is shingles treated?
Shingles heals spontaneously in principle. Usually pain relief and drying treatment for the blisters are sufficient, and sometimes bacterial infection of the damaged skin must be prevented or treated. When antiviral therapy is started within the first 3 days of an attack, the duration of the attack and of the pain is usually reduced. Antiviral therapy can be given as tablets and, in particularly severe cases, by infusion. It is started for shingles of the face, shingles in patients with strongly reduced resistance, and early shingles in older patients.
Can shingles be prevented?
It is now possible to prevent shingles with a vaccination. A large international study showed that vaccination protects against illness and against post-herpetic pain resulting from shingles.
What is the outlook?
Fortunately shingles usually occurs only once. If attacks recur, it is important to investigate for a disturbed or reduced immune defence.
When to see a doctor
See a doctor promptly for shingles on the face or near the eye, for severe or spreading shingles, if you have reduced immunity, or if severe pain persists after the rash has healed.