8 month old boy with impetigo caused by staph aureus on cheeks, chin, back of head, nipples, and rectal area. Had allergic reaction to Septra after 10 days, currently applying mupirocin and cortisone 2% 2 x day. Symptoms of impetigo began 4 months ago. Has been treated by family dr and dermatologist. Symptoms were getting better when on septra and mupiricin with steroid cream. Any suggestions for treatment ? Dermatologist said she has never seen impetigo this bad in 15 years of practice.