Hi I Have A 3 Year Old And He Keeps

Hi I have a 3 year old and he keeps waking up every morning with new bits . I don't know if there from a spider or what . I took him to his Dr for a check-up in to get medicine for his bites but the medicine doesn't seem to help what is it what can I do to help him from the itching and the redness and how soon can it be take you away