Definition and Overview
Shingles, known medically as herpes zoster, is a medical condition caused by the varicella zoster virus. Shingles is characterized by a rash found on a limited area of the skin. After childhood infection with the varicella zoster virus, the virus becomes latent; reactivation years after the initial infection causes shingles. In most instances, shingles goes away on its own, typically after 2 or 3 weeks. Shingles occurs more commonly in the older age group, and is believed to be due to decreased immunity in older individuals. An estimated 1 million people develop shingles in the United States every year. Shingles may recur although it is not common and usually develops just once.
Cause of Condition
Shingles is a reactivation of an infection with the varicella zoster virus. Thus, shingles can only appear in patients who have been infected with this virus in the past. The varicella zoster virus is what causes chickenpox in children. The chickenpox resolves when the body is able to fight off the infection and remove the virus in most areas of the body. However, the virus may not be completely eliminated and may become dormant in specific areas in the body, namely the dorsal root ganglion near the spinal cord. When the virus becomes active, shingles appear. The virus travels to the skin, causing inflammation and the characteristic rash. The virus also affects the nerves, resulting in pain.
In most people, the immune system is able to fight off the reactivation of the varicella zoster virus. Thus, patients who have impaired immune systems are at risk of developing shingles. These groups at risk include the elderly, cancer patients, people who are recipients of organ transplants, people who are stressed, and those who are immunocompromised.
Shingles initially presents with non-specific symptoms, such as fever and headache. This is then usually followed by pain or hypersensitivity. The pain of shingles has been described in various ways, such as burning, tingling, stinging, pricking and itching. In some patients, the sensation may be described as paresthesia or numbness with episodes of shooting pain.
Several days after the pain occurs, the classic rash then develops. This rash is limited to a specific dermatome, or an area supplied by a sensory nerve, in the body. The rash looks like a belt that is located only on one side of the body. This typically appears on the torso but may also occur on the face and other areas of the body. After a few days, the rash develops into fluid-filled blisters. The lesions eventually crust and fall off after a week or so, before fully healing.
If the dermatome involved is supplied by the ophthalmic branch of the trigeminal nerve, the eye may become affected. The patient may develop conjunctivitis, uveitis, and even loss of vision. This condition is known as herpes zoster ophthalmicus, and can happen in up to 25% of patients. Meanwhile, if the dermatome involved is the one that affects the ear, patients can develop dizziness and loss of hearing. This condition is known as herpes zoster oticus.
Who to See and Types of Treatments Available
The diagnosis of shingles is clinical. However, in questionable situations, your physician may ask for a skin biopsy in order to conclusively diagnose herpes zoster. If you experience pain or notice a rash in a dermatomal or band-like distribution, you should immediately see a health care professional. This is because antiviral drugs are effective only when administered early in the course of the infection.
If untreated, the symptoms of shingles are generally treated between two to four weeks. Treatment is directed at minimizing the pain involved with the condition and preventing the development of possible complications. Analgesics are the primary medications used in the treatment of shingles. For patients who experience severe pain, opioids or nerve blocks may be attempted. Meanwhile, lotions that contain calamine or petroleum jelly may help soothe the pain. The use of antihistamines may also help ease the itchy sensation and prevent unwanted scratching. Topical steroids may likewise be used in order to reduce the associated inflammation.
Antiviral medications, such as acyclovir and famciclovir, may also be administered to decrease the severity of the shingles. The duration of the pain and the rashes may be reduced. In patients with weakened immune function, the antivirals may have to be administered intravenously. The antiviral medications are only beneficial when given within 72 hours from the occurrence of the rashes.
Although the disease can resolve on its own, in certain instances, shingles can still develop serious complications. These include temporary facial paralysis, eye involvement and ear damage. Thus, in cases wherein a rash or pain develops on your face, especially if it spreads to the area near your eye, it is best to consult your health care provider. You should also seek consult if the rash becomes infected, which can present with swelling, erythema and pus. In these cases, antibiotics may be used to treat and prevent further spread of the superimposed bacterial infection.
In approximately 15-20% of patients with shingles, a condition known as postherpetic neuralgia, or PHN, occurs. Patients with PHN continue to experience the pain even when the rash is no longer there. Several medications may be used to manage this condition, including opioids like morphine or oxycodone, amitriptyline, and gabapentin. If the pain is severe, you may need to see a pain specialist to manage this condition.
A vaccine has been developed to prevent shingles. The live vaccine, named Zostavax, has been shown to reduce the risk of developing shingles by up to 50%. Studies have also shown that the vaccine can decrease the incidence of postherpetic neuralgia by approximately 66% in those patients who do develop shingles. There are minimal side effects, which are mostly localized to the injection site. This vaccine has been recommended for adults older than 60 years as a form of prevention.
Patients who have shingles are infective during the acute phase of the disease. At this time, it is important to minimize contact with the elderly, the immunocompromised, and people who have never had chickenpox.
- National Health Services. http://www.nhs.uk/Conditions/Shingles/Pages/Symptoms.aspx
- National Institute of Neurological Disorders and Stroke. http://www.ninds.nih.gov/disorders/shingles/shingles.htm