Chickenpox is a very contagious disease that is caused by the varicella-zoster virus. Chickenpox is usually a mild childhood rash illness, but it can cause serious complications, including pneumonia, inflammation of the brain tissue or inflammation of the coverings surrounding the brain and spinal cord, bacterial skin infections, and even death. Complications are more likely in older adults and those with weakened immune systems.
Anyone who has not had two doses of chickenpox vaccine or has not had the disease is at risk for getting chickenpox. Those less than one year of age and those over fifteen years of age are at greater risk for complications. People with weakened immune systems are also at greater risk for severe illness and complications. Chickenpox in pregnant women less than 20 weeks pregnant or during the week of delivery can result in severe birth defects and sometimes fatal illness in the infant.
Symptoms generally begin about 2 weeks after being exposed to someone with chickenpox or shingles. Symptoms include fever, fatigue, weakness, and rash. The rash first appears as flat, red bumps that become raised, filled with fluid similar to blisters (vesicles) and may severely itch. About five days after the rash appears, the blisters rupture and scab over.
Some children and adults who receive 1 or even 2 doses of the chickenpox vaccine will have a mild case of chickenpox known as breakthrough disease. When this happens, the disease is often very mild with fewer spots (often fewer than 50) that may not turn into vesicles, but look more like insect bites. A breakthrough case may never develop a fever during the course of illness. Lab testing is recommended to verify these types of cases, wherever possible, since other conditions could cause similar symptoms.
Diagnosis
Consult with your health care provider if you or your child has been exposed to someone with chickenpox or if either of you has symptoms. Your health care provider may collect blood or swab samples of the skin lesions to test for chickenpox. Chickenpox is most often diagnosed based on the symptoms experienced. If you or your child have ever had chickenpox or have received two doses of chickenpox vaccine, it is unlikely that you will get chickenpox. Many other organisms can cause rash illnesses than can resemble chickenpox.
Treatment
Treatment focuses on relieving the symptoms of the illness. Your doctor may recommend prescription or over-the-counter medications or lotions for symptoms. Fingernails should be trimmed to prevent infection from scratching, and bedding should be changed frequently to help prevent skin infections.
Chickenpox is spread from person to person through airborne nose and throat secretions or contact with skin lesions or lesion fluid. A person with chickenpox is considered highly contagious for at least 2 days before the rash appears until the rash has scabbed over. People who don’t develop vesicles are considered contagious until no new lesions have appeared in a 24-hour period. Much less commonly, a person can get chickenpox from direct contact with a person who has shingles lesions.
There is a safe and effective vaccine to prevent chickenpox. If you or your child have not had chickenpox, or have no record of having the chickenpox vaccine, talk to your health care provider to decide if you should receive the vaccine. In the state of Indiana, schools and licensed child care providers require proof of vaccination or history of having chickenpox for entry into school. Two doses of chickenpox vaccine provide the best protection against chickenpox. If someone at risk for getting chickenpox comes into contact with a contagious person, the vaccine can be given within 5 days of exposure to prevent disease or lessen symptoms if the person develops chickenpox.
Page last updated/reviewed: April 2026
