Fifth disease begins with mild symptoms, including a fever, muscle aches, headache and decreased activity for a few days. About 7 to 10 days later, affected children will develop a red rash on their cheeks, which takes on the typical 'slapped cheeks' appearance of Fifth Disease.Next, kids get a pink or red lacelike rash on their arms. This rash comes and goes and may spread to their legs, trunk and buttocks.
My Daughter had this when she was 5. It's not a major deal. I didn't even know she had it till her preschool teacher told me. It heals it self so no worries.
Could be dangerous if pregnant women are exposed to it. I was when I was pregnant with my son and I had to have several prenatal tests to ensure that he was alright.