Information on the following diseases can be found in the Related Disorders section of this report:

• Herpes Simplex (Fever Blisters; Cold Sores)
• Trigeminal Neuralgia (Tic Douloureux)

The varicella-zoster virus causes chickenpox in children. After exposure to the virus, the incubation period is between 11 to 21 days. The severity of the chickenpox ranges from a slight rash to many hundreds of blisters and a fever as high as 105 degrees F. Chickenpox symptoms begin with a slight fever, sore throat, runny nose and a general feeling of discomfort. This precedes the rash by a few days.

The rash first appears on the back and chest, quickly covering the body. Spots may also appear in the mucous membranes such as those of the mouth, vagina or in the ears. The rash develops quickly into clear, oval blisters of various sizes. These soon become cloudy in color and within three to four days turn to scabs. It may take another week for the scabs to fall off.

After the rash first appears, it will continue to erupt for three to four days, and is often very itchy. During this time, and until all the lesions are scabbed over a child with chickenpox is still contagious, and should be kept isolated.

In rare cases, chickenpox may cause life-threatening complications in children with a compromised immune system (e.g., primary immune deficiency disorders, individuals undergoing chemotherapy, or people with asthma who are taking steroid drugs for prolonged periods of time).

Shingles (herpes zoster) occurs when the varicella-zoster virus is re-activated for unknown reasons. It is a non-seasonal infection occurring most often in older people and in those whose immune system is suppressed. Nonimmune individuals, especially children, may develop chickenpox after contact with a person who has active herpes-zoster virus. Shingles first appears as a rash, similar to chickenpox, but finer in appearance. The rash usually occurs on one side of the body or face, in an area involving one particular spinal nerve.

The first symptoms of shingles may include chills, fever, and a feeling of discomfort; these symptoms typically develop three or four days before distinctive features of the disease develop. Pain may or may not occur along the site of the future skin eruption. On the fourth or fifth day, characteristic groups of blisters appear on a red base, distributed on skin areas that are served by one or more root nerve centers (posterior ganglia) along the spine. The involved skin area is usually extremely sensitive to touch (hypersensitive), and the associated pain may be severe. The eruptions occur most often in the chest area and may spread only on one side of the body. On about the fifth day, the skin lesions begin to dry and form scabs. Shingles rarely becomes generalized. If the lesions spread or persist for more than two weeks, additional special medical evaluation may be necessary.

One episode of shingles usually imparts immunity from subsequent attacks. Most individuals recover without any after effects, except for occasional scarring of the skin. However, in a small number of cases, nerve pain (neuralgia) may persist for months or years after the shingles rash disappears (postherpetic neuralgia or PNH). PNH occurs most frequently in elderly individuals. In some cases, pain associated with PNH may subside only to recur later.

Geniculate zoster (herpes zoster oticus or Ramsay-Hunt syndrome) is a form of postherpetic neuralgia that involves part of the facial nerve near the internal ear (geniculate ganglion). Pain in the ear and facial paralysis (rarely permanent) may occur on the affected side. Blisters may erupt in the external ear canal, the outer ear, the soft palate, and the top part of the throat. Some affected individuals may develop abnormalities such as ringing in the ears (tinnitus) and hearing loss. The pain is often described as a burning or stabbing pain.

Herpes zoster ophthalmicus involves the herpes zoster virus affecting the ganglion of the 5th cranial nerve (trigeminal or gasserian ganglion). Pain and an eruption of blisters in the distribution of the branch of the 5th nerve serving the eye occur. A 3rd nerve paralysis may be present. Blisters on the tip of the nose indicate that the branch of the 5th nerve serving the nose, eyes, eyebrows (nasociliary branch) and the cornea are involved. Development of corneal ulcerations and clouding (opacities) may also occur.

Some individuals with herpes zoster may have characteristic pain and evidence of the active virus in their body, but without any skin symptoms such as rash or blisters. These cases may be referred to as zoster sine herpete.

Varicella-zoster is an infectious disease. The varicella-zoster virus is a member of the herpes virus family. Chickenpox is transmitted in the form of airborne droplets (through the respiratory route). The virus lays dormant after the primary infection and may be activated as shingles later in life.

Chickenpox affects males and females in equal numbers. It is most common in between the ages of 5 and 9. Shingles usually occurs in adults over the age of 50. These disorders are very prevalent in the United States and throughout the world.

Symptoms of the following disorders may be similar to those of varicella zoster Comparisons may be useful for a differential diagnosis:

Herpes simplex (fever blister; cold sore) is a recurrent infection by the relatively large herpes simplex virus. It is characterized by the appearance on the skin or mucous membranes of clusters of small blisters, filled with clear fluid on slightly raised inflamed bases. There are two types of herpes simplex. Type 1 causes infections around the lips and in the cornea. Type 2 usually affects the genital areas and is transmitted primarily by direct contact with lesions, most often during sexual intercourse.

Trigeminal neuralgia (tic douloureux) is a nerve disorder characterized by attacks of acute pain at the side of the mouth and nose, along the distribution of the trigeminal nerve. (For more information on this disorder, choose "Trigeminal" as your search term in the Rare Disease Database.)

The Food and Drug Administration (FDA) has approved a vaccination against varicella (chickenpox) for children over the age of 12 months. Studies indicate that the vaccine is 70 to 90 percent effective. If chicken pox occurs in a child who has been vaccinated, symptoms may be milder than would otherwise be expected.

There is no specific treatment for chickenpox. However, calamine lotion has a soothing and drying effect on the rash and an antihistamine drug may be prescribed to reduce the itchiness. It is most important to keep the patient from scratching the blisters and scabs, because scarring and further infection can result. Acetaminophen, given every 4 hours will help reduce the fever and headache. Aspirin should NOT be given to children with chickenpox because it can cause Reye syndrome. (For more information concerning this disorder, choose "Reye"as your search term in the Rare Disease Database.)

For immunosuppressed individuals, antiviral drugs, such as acyclovir and vidarabine have been used, with acyclovir found to be the most effective. Until a vaccine for chicken pox becomes commercially available, children with a compromised immune system should guard against exposure to the varicella-zoster virus.

There is no specific therapy for shingles (herpes zoster). However, corticosteroids (if given early) may relieve pain in severe cases. Locally applied wet compresses may also be soothing. In addition, aspirin, alone or with codeine, may relieve pain. Immunosuppressed patients with herpes zoster may benefit from treatment with the antiviral drug adenine arabinoside (vidarabine) or intravenous immunoglobulin. Immunoglobulin can also be beneficial for prevention of herpes zoster infection in immune suppressed patients.

The antiviral drug Zovirax (acyclovir) is a standard therapy for herpes zoster and chickenpox. In 1992, the FDA approved its use in children with chickenpox who are otherwise healthy.

Clinical trials are being conducted on the experimental drug Arabinosyl adenine (ARA-A) for treatment of herpes zoster (shingles). Merck, Sharp & Dohme, is testing a chickpox vaccine.

Transfer factor from an individual with herpes zoster during the healing phase is being tested as treatment for individuals with a compromised immune system. Post herpetic neuralgia (intractable pain following shingles) has been observed in rare cases. Zostrix (capsaicin), a drug for treating this pain, was introduced into the United States and Canada in 1987. For more information, physicians can contact:

GenDerm Corporation
425 Huehl Road
Northbrook, IL 60062

Skin eruptions may heal faster with fibroblast interferon infused into the abdominal cavity. Low-frequency electrotherapy has also been used successfully. However, more research with these forms of treatment is needed to establish their safety and effectiveness. Injection of anesthetics into the painful nerves (nerve block) has been found beneficial for severe cases of postherpetic neuralgia.

The Lidocaine patch (5%) has received an orphan drug designation from the FDA for the treatment of post-herpetic neuralgia resulting from herpes zoster infection. More studies are needed to determine the long-term safety and effectiveness of this drug for the treatment of postherpetic neuralgia. For more information, contact:

Hind Health Care, Inc.
165 Gibraltar Court
Sunnyvale, CA 94089

Additional drugs that are being studied for postherpetic neuralgia and associated pain include the anticonvulsant drug, pregabalin, and divalproex sodium (valproic acid and sodium valproate).

Information on current clinical trials is posted on the Internet at www.clinicaltrials.gov. All studies receiving U.S. Government funding, and some supported by private industry, are posted on this government web site.

For information about clinical trials being conducted at the NIH Clinical Center in Bethesda, MD, contact the NIH Patient Recruitment Office:

Tollfree: (800) 411-1222
TTY: (866) 411-1010
Email: prpl@cc.nih.gov

For information about clinical trials sponsored by private sources, contact:
www.centerwatch.com

TEXTBOOKS
Isselbacher KJ., et al., ed. Harrison's Principles of Internal Medicine, 13th ed. McGraw-Hill, Inc. 1994;787-89.

Mandell G, et al., ed. Mandell Douglas and Bennett's Principles and Practice of Infectious Diseases, 4th ed. Churchill Livingstone Inc. 1995;1345-50.

JOURNAL ARTICLES
Hadj Tahar A, Pregabalin for peripheral neuropathic pain. Issues Emerg Health Technol. 2005;67:1-4.

Kochar DK, et al., Divalproex sodium in the management of post-herpetic neuralgia: a randomized double-blind placebo-controlled study. QJM. 2005;98:1:29-34.

Kennedy PG. Varicella-zoster virus latency in human ganglia. Rev Med Virol. 2002;12:327-34.

Hashizume K. Herpes zoster and post herpetic neuralgia. Nippon Rinsho. 2001;59:1738.42.

Poltera AA, et al., Acellular pertussis vaccines. N Eng J Med. 1996;334:1547-8.

Strauss SE, et al., NIH conference varicella-zoster virus infections. Biology, natural history, treatment, and prevention. Ann Intern Med. 1988198:221-237.

Shepp DH, et al., Current therapy of varicella-zoster virus infection in immunocompromised patients. A comparison of acyclovir and vidarbine. Am J Med. 1988;85:96-8.

Gershon AA, et al., Immunization of healthy adults with live attenuated varicella vaccine. J Infect Dis. 1988;158:132-3.

Johnson CE, et al., Live attenuated varicella vaccine in healthy 12-to-24 month old children. Pediatrics. 1988;81:512-8.

FROM THE INTERNET
National Institute of Allergy and Infectious Diseases. Facts About Shingles (Varicella-Zoster Virus. June, 2003. Available at: http://www.niaid.nih.gov/factsheets/shinglesFS.htm Accessed On: May 26, 2005.

National Institute of Neurological Disorders and Stoke. Shingles Information Page. March 9, 2005. Available at: http://www.ninds.nih.gov/disorders/shingles/shingles.htm Accessed On: May 26, 2005.

Anderson WE. Varicella-Zoster Virus. eMedicine Journal. 2005. Available at http://www.emedicine.com/med/topic2361.htm Accessed On: May 26, 2005.

McElveen WA. Postherpetic Neuralgia. eMedicine Journal. 2002;3:11pp. Available at: http://www.emedicine.com/neuro/topic317.htm Accessed On: May 26, 2005.