How Long Does Impetigo Takes To Cure ?

hello, im a 40 yr old black female who was diagnosed with impetigo on oct 15. on my last visit the diagnoses was changed to impetigo herpetiformis. originally treated with doxycycline hyc 100mg and mupirocin. after an er visit was changed to sulfameth/tmp, prednisone 20 mg, rifampin 300 mg, and a pain and anti-itch pills. follow up visit changed dianoses and treatment to keflex 500mg(which i have started taking) and betamethasone valerate 01% (which i will start friday nov. 4). what i need help with is how long does it take to get some relief for the itching, burning and pain.