hives from a virus in child
1 Widespread hives usually are caused by a viral infection. 2  Can also be an allergic reaction to a food, drug, infection, insect bite, or other substances. 3  Often, the cause is not found. 4  Hives from foods usually resolve in 6 hours. Contagiousness: Hives are not contagious. 2  Your child can return to child care or school if the hives do not interfere with normal activities. 3  If the hives are associated with an infection, your child can return to school after the fever is gone and your child feels well enough to participate in normal activities.