My 9 year old son woke up yesterday with itching on his scalp, hands, feet, torso, and neck. I gave him Benadryl and he got over and seemed fine. Last evening he started to complain of severe pain in his ankles. He went on to bed, but woke up at 4 AM width severe itching again and his wrists were hurting. I gave him more Benedryl which helped the itching, but his joint pain has spread to some of his knuckles. Also, a new itchy spot just popped up on the side of his knee. This new spot also hurts when I press on it. He had been on Amoxicillin for a cold he had about a week ago but we were told to stop that medication by an after hours physician this morning. Does this sound like an allergic reaction to the meds?