My 5 year old was strep positive 2 weeks ago. Symptoms (low grade fever , nausea , excessive thirst, rash on cheek) started up again the day after our 1st round of antibiotics were complete. Another strep test was done and it came back negative. Received antibiotics just in case while the sample was sent out to be double checked. Other than strep, what would cause this? My daughter is a healthy eater (Fruit and vegi daily), yet she s been sick with one thing or another 6 of the last 8 weekends.