Infectious Diseases

Chickenpox: Causes, Treatment, and Vaccine

Written by
Dr. Vasantha K S
and medically reviewed by Dr. Velusamy M.p

Published on Jan 17, 2018 and last reviewed on Sep 07, 2018   -  3 min read



This article addresses the causes, symptoms, spread, risk factors, complications, and treatment of chickenpox.

Chickenpox: Causes, Treatment, and Vaccine

Chickenpox is a common childhood viral disease, that develops in persons not previously exposed to chickenpox, not vaccinated against chickenpox and in recent contact with persons having chickenpox or shingles. Although it is more common in children from 5 to 12 years of age, it can occur in any age group including adults.

Causes of Chickenpox

It is an infection that classically presents with rashes and fever. It is caused by a virus called varicella zoster. This infection has an incubation period of seven to 21 days, meaning it may take up to those many days for symptoms to appear after the virus enters the body.


Itchy rashes are the primary symptom. Other symptoms can appear earlier, even before the appearance of rashes:

  1. Tiredness.
  2. Headache.
  3. Body pain.
  4. Fever.
  5. Loss of appetite.

More about the rashes

The rashes go through different stages namely:

  • Papules - similar to pimples or insect bites, this is how they begin.
  • Vesicles - they progress to fluid-filled blisters that form raised bumps.
  • Crusts - once the blister breaks and the fluid ooze out, they dry out forming scabs.

This process takes about a week. They usually start to appear in the head and trunk and then spread to the arms and legs. Since the new rashes develop in waves, there are multiple rashes all over the body each at a different stage. Most cases of chickenpox get completely cured in a period of two weeks.

How does it spread

Direct spread through skin to skin contact, or contact with oral droplets during coughing and sneezing, or touching the fluid from the blisters.

Indirect spread through contact with contaminated objects such as doorknob, clothing, and toys.

Complications in Chickenpox

  1. Shingles: Once a person has chickenpox, the varicella zoster virus stays on in the nerve cells in a dormant state. If it gets reactivated later in life, it causes a nerve infection known as shingles.
  2. Bacterial infection on skin: Since there are so many itchy open sores on the body, children tend to unknowingly scratch them depositing the bacteria in their nails into the skin and thus causing a skin infection.
  3. Sepsis: It can occur as a result of bacteria entering the bloodstream from the infected blisters.
  4. Reyes's syndrome: It is a fatal complication associated with Aspirin intake during chickenpox episode. Aspirin should NOT be given to children to treat fevers caused by varicella zoster.
  5. Pneumonia: This complication is more probable in pregnant women with chickenpox infection.
  6. Other less common complications include dehydration, meningitis, and encephalitis.

Risk factors

A person with chickenpox usually recovers without any antiviral treatment. But antivirals are given in case of persons at high risk of complications such as:

  1. Infants.
  2. Teenagers.
  3. Adults.
  4. Pregnancy.
  5. Immunocompromised (HIV).
  6. Leukemia.
  7. Cancer.
  8. Chemotherapy.
  9. Autoimmune diseases.
  10. Immunosuppression drugs.

How can chickenpox be prevented?

Varicella vaccines are available as a combination and are part of the regular immunization schedule regime in most countries. The first dose is given at 1 year and the second booster dose is given at 4 years. For non-vaccinated adults in close contact with infected children or adults, the vaccine can be given any time required.

Home management

The prime requirement in home management will be to care for the itchy blisters.

  • Keep away from daycare, school or work in order to prevent spread and ensure rest and hydration.
  • A bath can be taken once a day with mild lukewarm water and no soap. Adding plain oatmeal to the bath has known to help soothe skin wounds.
  • Applying a non-scented lotion after a bath helps with the dryness especially the rashes in the scabs stage.
  • Wearing loose cotton clothes is preferred.
  • Trim nails to prevent itching and secondary infection.
  • Put mittens or socks to the hands of young kids to prevent them from scratching.


Antivirals such as Acyclovir is prescribed if the patient is in the high-risk category. If not, the infection is allowed to run its course.

- Acetaminophen (Tylenol) for fever and pain.

- Antihistamine to control the itching.

- Lacto calamine to soothe the skin.

Chickenpox and Pregnancy

Chickenpox during pregnancy is associated with a lot of serious risks. There is a higher risk of the mom developing pneumonia. She can pass on the infection to the fetus as well (known as fetal varicella syndrome) causing birth defects.

When to see the doctor?

See the doctor if:

  • you are pregnant,
  • you have unexplained rashes with fever symptoms,
  • the rash spreads to the eyes,
  • the rash is tender and warm,
  • there is dizziness or breathing difficulties.

For more information consult an infectious diseases specialist -->

Last reviewed at:
07 Sep 2018  -  3 min read




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