Chickenpox: what you should know about this infectious disease

Chickenpox is the common name for simple chickenpox, classically one of the childhood infectious diseases that most children contract and survive.

Chickenpox is caused by the varicella-zoster virus. It begins with a moderate fever and then characteristic spots that appear in two or three waves, mainly on the body and head rather than on the hands and develop into raw itchy pox (pox), small open sores that heal mostly without leaving scars.

This infectious disease has an incubation period of two weeks and is highly contagious by airborne transmission two days before symptoms appear. Therefore, it spreads rapidly through schools and other places of close contact.

Once someone has been infected with the disease, they usually develop lifelong protective immunity. It is quite rare to get chickenpox multiple times, but it is possible for people with irregular immune systems.

As the disease is more serious if contracted by an adult, parents have been known to ensure that their children are infected before adulthood.

The disease can be fatal. Pregnant women and those with suppressed immune systems are more at risk. Death is usually due to varicella pneumonia. In the US, 55 percent of chickenpox deaths occurred in the 20-plus age group. Pregnant women who are not known to be immune and who come into contact with chickenpox should contact their doctor immediately, as the virus can cause serious problems for the fetus.

The vaccine has been available since 1995 and is now required in some countries for children to be admitted to primary school. In addition, there are effective drugs (eg, acyclovir) to treat healthy and immunocompromised people. Calamine lotion is often used to relieve itching and paracetamol to reduce fever. Aspirin is not recommended in children, as it can cause Reye’s syndrome.

Chickenpox is an infection that spreads from person to person by direct contact or through the air from a cough or sneeze of an infected person. Touching fluid from a chickenpox blister can also spread the disease. A person is contagious 1-2 days before the rash appears and until all the blisters have crusted over. This can take between 5-10 days. It takes 10 to 21 days after contact with an infected person for someone to develop the disease.

The blisters begin as a small red papule that develops an irregular rose petal-shaped outline. A clear, thin-walled vesicle (dew drop) develops over the area of ​​redness. This “dewdrop on a rose petal” lesion is very characteristic of chickenpox. After about 8-12 hours, the fluid in the gallbladder becomes cloudy and the gallbladder ruptures, leaving a crust. The fluid is highly contagious, but once the lesion forms a scab, it is not considered contagious. The scab usually falls off after 7 days, sometimes leaving a crater-like scar.

Although a lesion goes through this complete cycle in about 7 days, another characteristic of chickenpox is the fact that new lesions appear every day for several days. Therefore, it may take about a week for new lesions to stop appearing and existing lesions to scab over.

Second infections do occur in immunocompetent individuals but are rare and seldom serious.

Japan was one of the first countries to routinely varicella against chickenpox. Routine varicella zoster virus vaccination is also carried out in the United States, and the incidence of chickenpox has dropped dramatically from 4 million cases per year in the pre-vaccine era to approximately 400,000 cases per year starting in 2005.

The vaccine is extremely safe: About 5% of children who receive the vaccine develop a fever or rash, but there have been no deaths, as of May 2006, attributable to the vaccine despite more than 40 million doses being administered.

41 of the 50 US states require vaccination of children attending government-run schools. Vaccination is not routine in the UK. Debate continues in the UK about when it will be desirable to adopt routine vaccination, and views are also being expressed in the US that it should be phased out, individually or together with all vaccines.

The CDC and relevant national organizations are carefully watching the failure rate that can be high compared to other modern vaccines: there have been large outbreaks of chickenpox in schools that required their children to be vaccinated.

It is believed that contracting wild chickenpox as a child usually results in lifelong immunity. Parents have deliberately ensured this in the past with reports of smallpox and similarly for some other diseases such as rubella.

Historically, exposure of adults to contagious children has increased their immunity, reducing the risk of shingles.

Disclaimer: This article should not be a substitute for medical advice. Talk to a qualified professional for more information about chickenpox.