Hi,

There are no guarantees when it comes to sinus infections.

That said, a fairly common regimen for folks with allergy related sinus issues is:
--oral antihistamine (clarinex/claritin, zyrtec or allegra - those are the only nonsedating ones currently available. Allegra doesn't work for me, I use claritin)
--inhaled steroid (flonase, rhinocort, nasonex)
--sudafed (not needed separately if you use claritin-d or allegra-d)

Sinus irrigation will not necessarily prevent infection, although it can by flushing mucus out and keeping sinuses cleaner. it can also mitigate infection.

I also use Astelin nasal inhaler - it's an antihistamine nasal inhaler in addtion to the meds above.

It is important to take these meds even when you are feeling well, to prevent reaction.

Also, I have had as many as 9 sinus infections in a year, all allergy related.

Hope you are feeling better soon.