Hello There, My Son Came Home From School With Bug

Hello there, my son came home from school with bug bites on one of his legs and the trail was a line, I figured it might be scabies because he was diagnosed once before. So I put the ointment on his bites and also hydrocortisone but I think I either put to much or it wasn’t suppose to be mixed because two of his bites look like it was chemically burned to the point two of his bites turned into one small blister and one medium size one. He has showered since then and I haven’t put anything else on it as soon as I saw why his leg was hurting. He says he isn’t in pain unless you touch the blister. Should I let keep them covered with a band aid and let them pop on their own or take him to the hospital?