Feed and farm stores have some antibiotics, such as Tylan, oxytetracycline, and tetracycline. for respiratory diseases, and in the refrigerated section, injectable procaine penicillin G for staph and wound infections. Vets can give somewhat better antibiotics for wounds such as clavamox...
Welcome to BYC. Since it has been there almost from birth, without evidence of a respiratory disease such as MG or coryza, I would guess that the bump could be a hemangioma, cyst, or tumor. It it came on more recently, then I would suspect a respiratory disease that was causing a sinus...