Chickenpox | Symptoms & Causes

What causes chickenpox?

Chickenpox is extremely contagious. It spreads from person to person by direct contact or through the air.

  • Chickenpox is contagious for one to two days before the appearance of the rash and until the blisters have dried and become scabs.
  • Children should stay home and away from other children until all of the blisters have scabbed over.
  • Family members who have never had chickenpox have a 90 percent chance of becoming infected when another family member in the household is infected.
  • Most individuals who have had chickenpox will be immune to the disease for the rest of their lives. However, there is a chance of developing shingles later in life, or even a secondary case of chickenpox.

What are the symptoms of chickenpox?

Symptoms are usually mild among children, but may be life-threatening to infants, adults and people with weak immune systems. While symptoms vary from child to child, the most common include:

  • fatigue and irritability one to two days before the rash begins
  • itchy rash on the trunk, face, under the armpits, on the upper arms and legs, inside the mouth, and, sometimes, in the windpipe and bronchial tubes
  • fever
  • decreased appetite
  • muscle and/or joint pain
  • cough or runny nose

Infants, adults and people with weak immune systems who get chickenpox are at risk for serious complications. They include:

  • secondary bacterial infections
  • pneumonia
  • encephalitis (inflammation of the brain)
  • cerebellar ataxia (defective muscular coordination)
  • transverse myelitis (inflammation along the spinal cord)
  • Reye syndrome (a serious condition which may affect all major systems or organs)
  • in extremely rare cases, death