My son was diagnosed with a throat infection Tuesday night. He s been on amoxicillin since then. When I took him in, he had a small rash around his mouth which I figured was from infected saliva (he ll be 4 yrs old in June). Yesterday the rash turned into what looks like popped blisters. No puss or clear liquid has come from them. Also he developed pin sized red dots on his hands and ears. Today his mouth looks the same but his hands look like they have darkened. No more dots, but a little swollen. His ears have gone red, like he d been sleeping on them. And now he has these darker redish patches on his feet - around the big toe. He been on Amoxicillin before so I don t think it s a reaction to the meds but what else could it be? Also my daughter, who is not being treated has developed the dots on her hands and a fever? Do I need to rush them to the ER?