When a child develops an itchy rash, many parents immediately worry about chicken pox. But thanks to vaccination, most rashes in school-age children are caused by something else entirely. Pediatrician Cindy Gellner, MD, debunks chicken pox myths. Learn how to tell when a rash might not be chicken pox, what conditions commonly mimic it, and when to call your child's pediatrician about a suspected chicken pox rash.