"Yes, it could be a 'slapped cheek' appearance due to Fifth Disease. It is called Fifth Disease because it was the fifth disorder in the classification scheme of childhood rashes at the time it was identified," says Lawrence Fan, MD, a Kelsey-Seybold pediatrician at Fort Bend Medical and Diagnostic Center.
"Fifth disease, also known as 'Erythema Infectiosum,' is caused by human parvovirus B-19 (not the parvovirus which causes disease in cats and dogs). It typically starts out causing a bright red rash on the cheeks. This is followed by a lacy red rash, which frequently spreads down the trunk and extremities over the next week or so."
Dr. Fan notes that Fifth Disease usually affects children, but adults also can be infected. "In children, the disease can occasionally cause fever, mild itching, malaise or headaches. The biggest danger is that infection in a pregnant mom can cause damage to the fetus. People who have Fifth Disease are probably not contagious once the rash breaks out. It is difficult to know when someone is contagious as he or she usually will not have any symptoms before the rash starts. Therefore, children usually do not need to miss school once the rash breaks out."