Allergies or a sinus infection, what's the difference?

That is a million: dollar question! In theory - allergies are cause by environmental triggers and cause inflammation. A sinus infection is caused by a bug - virus, fungus or bacteria. Many sinus sufferers have allergies - but not all. Some chronic sinusitis is caused by very narrow anatomy in sinus cavities. Careers have been made trying to answer these questions effectively in a given person