CHICKENPOX is the colloquial term for the viral illness that is caused by the varicella zoster virus.

It is highly contagious and results in vesicles (small blisters), rashes, and erythematous (red) spots all over the skin. This rash is intensely itchy and makes the condition distressing and uncomfortable.

The varicella virus is transmitted when the infected person coughs, sneezes or exchanges bodily fluids, like when sharing utensils, soap, and other personal items during the infectious phase. This occurs a few days before the blisters appear, and continue during the phases of the rash when crops appear on the skin, and until they have dried up and crusted.

Symptoms

The incubation period once infected is about 14 days after contracting the virus. The first symptoms to appear are similar to that of a viral illness — sore throat, headache, fever, feeling unwell, decreased appetite, and tiredness. In approximately two days the rash appears. It can be mild or could spread all over the skin and mucous membranes like the eyes, throat, vagina, and anus.

It starts as pink or red spots and then blisters (fluid-filled bumps), bursts, dries up, and then forms

a crust or scab. They appear in groups for up to a week. In about 10 days the rashes dry up and the person is no longer able to pass on the virus.

Who is at risk?

Chickenpox affects all age groups and does not cause a severe illness in healthy people with a normal immune system. It is often contracted in childhood and healthy children recover quickly. People who experience severe illness are usually adults and those with weakened immune systems, such as newborns whose mothers never had chickenpox or the vaccine, pregnant women, the elderly, and the immunocompromised (diabetics, people with AIDS, patients on steroids, or have cancer). These people should see their doctor for evaluation and treatment.

Diagnosis

Chickenpox is easily diagnosed by the characteristic appearance of the rash by the family physician or general practitioner.

Treatment

Treatment of chickenpox for healthy individuals is largely supportive: eating a healthy diet, resting, taking medication for the pain (such as paracetamol) and for the itching, such as antihistamines (diphenhydramine [dph] ), or using anti-itch creams such a calamine lotion. Aspirin should be avoided as it can cause a serious disease called Reyes Syndrome. Antiviral medication such as acyclovir or valacyclovir can reduce the symptoms if prescribed in the first 24 hours after the rash appears. Immunoglobulin is indicated for people who are severely ill.

The varicella virus stays in the body in the nerves and can be reactivated later in the form of shingles, a painful rash affecting sections of the skin. This usually affects the elderly and patients whose immune system is weakened such as diabetics, people with cancer, those infected with HIV/AIDS, or those on steroids.

Complications

Chickenpox can cause complications such as pneumonia and bacterial skin infections, infections in the bloodstream (sepsis), inflammation of the brain and severe illnesses such as toxic shock syndrome. Pregnant women can have babies who are of low birth weight or have birth defects, especially if contracted one week prior to delivery. However, most healthy adults recover completely, except with a few spots on the skin, especially if the vesicles were scratched and the skin torn resulting in a scar.

Prevention

Prevention of chickenpox is by avoiding those who are infected and by getting two doses of the varicella vaccine. A few people may get the disease even after vaccination, but the disease course is lessened and the complications are reduced.

All health care workers who have not contracted the disease prior to employment should be vaccinated as the virus is highly contagious. People who are exempt from getting the vaccine are persons who are pregnant, immunocompromised, had the disease before, or are allergic to gelatin and neomycin. A blood test can determine if antibodies are present to the virus if the person is in doubt that they had contracted the disease.

It is also rare but possible to contract the disease more than once, as usually it confers lifetime immunity. It is also possible to get chickenpox from exposure to the fluid from the vesicles of people with shingles.

Dr Romayne Edwards is a consultant emergency physician at the University Hospital of the West Indies and an associate lecturer at the University of the West Indies.