You may have to seek a PD's or dermatologist's advice. My boy had these insect bites but after the smaller red spots appear, we went to KKH and he was diagnosed with HFMD. We learnt that the smaller spots were HFMD spots. Mouth ulcers and spots are usual symptoms, but they may not appear in every child. Like in my son's case, he only had the spots on his calves and did not have them on his feet or hands, and did not have ulcers in his mouth too.