A: Fifth disease is an illness common in school-age children during the late winter and early spring, caused by the parvovirus (but not the same one that shows up in pets). Fifth disease earned the name "slapped cheek" because the symptoms include a distinctive blotchy, red rash that starts on the face and looks as though the child was hit (it also spreads to the trunk, arms, and legs). Fever and a runny, stuffy nose are also typical side effects.
Fifth disease is only contagious until the rash breaks out, but it's tough to diagnose before then, which means many kids remain in school when they're most communicable. The disease spreads through sharing infected objects, like toys and school supplies, or playing with sick kids. Once a child catches the virus, it can take two to three weeks for symptoms to show up, and about that long for the rash to go away (although children can return to school before then since they're no longer contagious).
If your child develops a red, blotchy rash, you should visit your pediatrician. She should be able to diagnose fifth disease just by looking at it, but if she's uncertain, a blood test for parvovirus can be done. It's important to get a firm diagnosis because you'll want to let your child's school or daycare center know that the other kids and teachers have been exposed. There's no fast treatment for fifth disease; the illness just has to run its course. In most cases, kids don't get that sick and recover quickly. Giving your child an age-appropriate dose of Tylenol or ibuprofen can help lower his fever if he's uncomfortable. Luckily, most kids develop immunity to the virus after catching it, so they most likely won't get it again.