How is it spread?
Chicken pox is very contagious. It is a respiratory disease that is spread by contact with nasal mucus and saliva. it can be spread by coughing and sneezing, kissing on the lips and sharing food, eating utensils and mouthed toys. It is also spread by touching your hands to your nose and mouth, reusing tissues, and forgetting to wash your hands after blowing noses. It spreads most easily in crowded and poorly ventilated rooms. Rarely, it can also be spread from contact with the oozing skin lesions.
When is it contagious?
Chicken pox is contagious from 2 days before the rash appears until 5 days after the start of the rash. In milder cases, the contagious period may end sooner, around the time that the pox scab over. After exposure to chicken pox, it usually takes 11-14 days (up to 21 days) to develop the illness.
Should the child stay home?
A child with chicken pox should stay home until 6 days after the start of the skin rash or when all the skin lesions are scabbed over, whichever is earlier.
If the child was still contageous than that is just plain mean and dangerous.