Can there be any way to cure a sinus infection without antibiotics?

Yes: Most cases of sinusitis will resolve spontaneously without antibiotic treatment. The current recommendation is to use antibiotics only for the most severe and persistant, over 7-10 days duration, cases. Use of symptomatic treatment such as pseudephdrine decongestant pills and neosynephrine decongestant nasal spray or nose drops and tylenol (acetaminophen) for pain may help.