Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at January 28, 2016

Chickenpox is a disease characterized by red, itchy spots all over the body. It is caused by a virus, and it is very contagious. It is not very common because children are immunized or vaccinated when they are young.


Definition & Facts

Chickenpox is caused by the varicella zoster virus, and it is most often seen in children. Most children display flu-like symptoms and a red, itchy rash that lasts about a week, during which time they need to be isolated from others. Until 1995, when a chickenpox vaccine was introduced in the US, most children had to suffer through the itchy rash for about a week. Since then, the occurrence of chickenpox has decreased dramatically.

Though extremely contagious, chickenpox is usually a mild disease in most children. However, it has the potential to be serious in some people, especially pregnant women and those with compromised immune systems. Additionally, there is a risk of complications from the chickenpox that can be avoided by being vaccinated.

Symptoms & Causes

The first symptoms of chickenpox may seem to be like any other cold, flu, or virus. Early symptoms can include stomach ache, sore throat, headache, a general sense of not being well, and fever up to 102 degrees Fahrenheit or 38.8 degrees Celsius. These symptoms may last a few days before the appearance of the characteristic rash.

It begins to appear first on the stomach, back, or face. It will quickly spread to all other parts of the body, including arms, legs, scalp, and inside the mouth. In more serious cases, it can also appear in the eyes, throat, anus, and vagina.

The classic chickenpox rash has three distinct stages. The rash pops up in clusters of red bumps that initially can look like pimples or insect bites. These bumps then develop into thin walled blisters with fluid inside that will burst as time goes on. After bursting, the blisters will dry up and appear as brown, crusty scabs that will take a few more days to heal. New bumps can continue to appear for several days.

The entire rash is very itchy and a patient is contagious until scabs form on all parts of the rash. All stages of the rash can appear on the body at the same time, in different places. Typically, the younger the patient is, the less severe the chickenpox will be.


Chickenpox is caused by a virus, is very contagious, and easily spread. Chickenpox can be spread through the air via coughing or sneezing. It can also be spread through mucus, saliva, and fluid from the rash. Chickenpox can be spread from about two days before a patient develops the rash, until all the blisters have dried up and scabbed over. A person can also develop chickenpox after exposure to a person who has shingles. Shingles is a disease that older persons can get when the varicella zoster virus is reactivated in a person who had chickenpox as a child.

Diagnosis & Tests

A doctor can usually diagnose chickenpox just from seeing the telltale rash. Additionally, other symptoms the patient may have, or recently had, can help in the diagnosis process. A patient will also want to note if they have been in contact with anyone who may have had chickenpox or shingles within the last two weeks. If there is still any doubt in diagnosis, blood tests are one way to tell for certain. In addition, lab tests to culture samples of the fluid from the lesions can be performed.

Treatment & Therapy

Most patients will not need any treatment for chickenpox. Some doctors may prescribe an antiviral drug, but this is usually only in cases where the patient has some other risk factors. Antibiotics are not used except in cases where the rash gets infected, usually from scratching. Discourage scratching by wearing gloves or socks on the hands, especially at night, and be sure to trim nails and keep them clean.

Cool baths, especially with oatmeal, and calamine lotion may be used to help with the itching. A physician may be able to recommend other creams for itching or pain, but be sure to check first. Acetaminophen may be used to ease pain, especially if rash sores are in the mouth, but never give aspirin to children with chickenpox. Aspirin is associated with a rare but serious disease in children called Reye's syndrome. Additionally, soft, bland, and cool foods will allow the patient with mouth sores more comfort when eating.

While a doctor’s treatment is usually not needed, do call if the patient has a fever that lasts for more than four days or if the fever is more than 102 degrees Fahrenheit or 38.8 degrees Celsius. Additionally, if areas of the rash leak yellow pus or are red, warm or swollen, this can mean there is a bacterial infection, and further treatment may be needed. Other rare complications that require a doctor’s visit are: severe cough or difficulty breathing, severe headache, extreme tiredness or trouble waking up, trouble walking, confusion, or stiff neck.

Prevention & Prophylaxis

Chickenpox can be prevented about 99% of the time when a chickenpox vaccine is given. It is a safe, effective vaccine that is recommended for over 90% of patients. It is recommended that children receive the vaccine between 12-15 months of age. A booster vaccine should follow between 4-6 years old. Older children who did not receive the vaccine as babies should receive two doses, approximately three months apart. Anyone over the age of 13 should also receive two doses of the vaccine. Their doses should be at least 28 days apart for full protection.

The only other way to prevent the spread of chickenpox is to isolate the patient with the disease. Since it is very contagious, the patient should be kept away from all who have not either had the disease or the vaccine when possible. Frequent hand washing will also be helpful in the prevention and spread of chickenpox.