My son Harbor visited our doctor today. He has folliculitis on his face around the mouth and diaper area. He has a couple of bumps spreading to his knees and to his cheek and ears. Our dog ironically developed the same thing on her stomach last week and we took her to the vet Friday. He diagnosed her bumps as staph dermatitis and put her on an antibiotic as well. My son is on cephalexin 7.5 ml, 2 times per day for 7 days, 250 mg/5 ML suspension. How long is he contagious to others? Is it possible to get this infection from our dog, or coincidental? Our older daughter had two bumps on her face and one on her nose, but has left them alone and they are getting better with polysporin alone.