My 4 Year Old Son Is Under Treatment For Scarlet

My 4 year old son is under treatment for Scarlet Fever for last 12 days. He is having cough and very unwilling to eat food. His antibiotic (Sefdin) has just been finished, but glands at cheek are still swollen.
Can we use some supplement like cobadex for him? Would his glands get reduced soon? or will it take time? if so, how many days may it take, please mention, as I am feeling very anxious.