Hello, I understand your concerns. A rash is a symptom of a viral illness,of which FIFTH disease is one type. Headache, runny nose and fever are the other symptoms that accompany fifth disease. My suggestion is paracetamol if she has fever, and an antti-histamine like cetrizine if she has itching. The rash will subside in a week and does not need any particular treatment. It is normal for school going children to have swollen tonsils. You have to take her to the doctor if she has pus coming from her tonsils, is unable to drink or eat anything or is drowsy all the time. Otherwise she will recover in the next week. Hope this helps !