Chickenpox is an infection caused by the varicella-zoster virus. It causes an itchy rash with small, fluid-filled blisters. Chickenpox is highly contagious to people who haven't had the disease or been vaccinated against it. Today, a vaccine is available that protects children against chickenpox. Routine vaccination is recommended by the Centers for Disease Control and Prevention (CDC). The chickenpox vaccine is a safe, effective way to prevent chickenpox and its possible complications.
Symptoms:
The itchy blister rash caused by chickenpox infection appears 10 to 21 days after exposure to the virus and usually lasts about five to 10 days. Other signs and symptoms, which may appear one to two days before the rash, include:
• Fever
• Loss of appetite
• Headache
• Tiredness and a general feeling of being unwell (malaise)
Once the chickenpox rash appears, it goes through three phases:
• Raised pink or red bumps (papules), which break out over several days.
• Small fluid-filled blisters (vesicles), which form in about one day and then break and leak.
• Crusts and scabs, which cover the broken blisters and take several more days to heal.
New bumps continue to appear for several days, so you may have all three stages of the rash — bumps, blisters and scabbed lesions — at the same time. You can spread the virus to other people for up to 48 hours before the rash appears, and the virus remains contagious until all broken blisters have crusted over.
The disease is generally mild in healthy children. In severe cases, the rash can cover the entire body, and lesions may form in the throat, eyes, and mucous membranes of the urethra, anus and vagina.
Causes:
Chickenpox infection is caused by a virus. It can spread through direct contact with the rash. It can also spread when a person with the chickenpox coughs or sneezes and you inhale the air droplets.
Risk factors:
Your risk of becoming infected with the varicella-zoster virus that causes chickenpox is higher if you haven't already had chickenpox or if you haven't had the chickenpox vaccine. It's especially important for people who work in childcare or school settings to be vaccinated.
Most people who have had chickenpox or have been vaccinated against chickenpox are immune to chickenpox. If you've been vaccinated and still get chickenpox, symptoms are often milder, with fewer blisters and mild or no fever. A few people can get chickenpox more than once, but this is rare.
Diagnoses:
Doctors generally diagnose chickenpox based on the rash. If there's any doubt about the diagnosis, chickenpox can be confirmed with laboratory tests, including blood tests or a culture of lesion samples.
Treatment:
In otherwise healthy children, chickenpox typically needs no medical treatment. Your doctor may prescribe an antihistamine to relieve itching. But for the most part, the disease is allowed to run its course.
