My 5 yr old has now had 4 course of penicillin for a recurring sore throat/ strep. looks like his coming down with it again. anymore explications?

Carrier vs resistent: Many times a recurrent symptomatic strep can be resolved by a 2 step treatment, a penicillin or cephalosporin followed on the last 4 days by using rifampin. If this works, fine. If you are testing + for strep but not sick with it, you could be a carrier ; the 2 step may help but not stop returning to carrier status.5 documented strep/yr will get the attention of many ent's ; a tonsil removal.