I used to be plaqued with sinus infections, and constant problems with allergies.
There are no "cures" per say, but if the sinus trouble is related to allergies, then it is an over active immune system. There are many different approaches to getting the immune system to quit reacting to these proteins.
Theory number one, histamine is produced to conteract the allergen protein, in theory you may not be able to digest proteins, and thereby putting more stress on the immune system, and causing it to over react.
The answer? digestive enzymes, such as QBC, quercitin bromelain complex. Bromelain helps you to digest protein, and is produced from pineapple, and found in meat tenderizers. Quercitin, is derived from citris, and is a natural antihistamine, no side effects like jitters ect. and the c is vitamin c, a natural anti inflammatory and decongestant, magnesium is calming to the brain, and body, as well as the immune system.
For sinus infection caused by bacteria, olive leaf, and grapefruit seed extract, available in a premixed formula, as a sinus cleanser. Both are a natural anti biotic, and anti inflammatory, if the mucus is green, its an infection. Garlic capsules, 2 times a day, will have it cleared in no time.
Theory 2, an unbalanced intestinal tract can cause reacurring infection. The answer probiotics.
Theory 3, leaky gut sydrome, proteins leak through actual holes in the gut or colon, causing an over ractive immune system, too many antibiotics, or steriods, as well as intestinal parasites, or infection. can cause this problem. The answer l-glutamine, an amino acid that actually repairs, the intestinal tract.
change your toothe brush, or run in the dishwasher, if you are prone to chronic sinus infection, it may be your just reinfecting yourself.
For doseage amounts and where to order:
an elimation diet, such as renegadetory suggests, is also a good idea, For dosage amounts as well as where to order http://hubpages.com/health/Is-it-a-cold-or-allergy...
Your particular situation, and other symptoms will lead you on the path to wellness.
I used the sinus spray, olive leaf orally, and QBC, for about a year, and nock on wood, havn't had another problem since. Naturals are always my first line of defense.