People without symptoms can spread the infection. Contagious from seven days before to four days after rash appears. Child should stay home for seven days after rash appears and should avoid contact with non-immune pregnant women. Siblings may continue to attend school or daycare as long as they are uninfected and have been immunized against the disease. Most often appears on neck, chest, folds of armpits, elbow, groin, and inner parts of thighs.
Symptoms appear one to three days after exposure.
Spread through direct contact with phlegm, saliva, or articles soiled by the sick child. Limited spread through the air. People without symptoms can spread the infection. Contagious for 10 to 21 days after exposure, or 24 to 48 hours after antibiotics have been started. Spread person to person.