You should also have yourself checked for food intolerances, and regardless of the outcome eliminate dairy and wheat from your diet for 10 days to see if it helps. Dairy and wheat are both known to be mucus forming and are often the key cause of the sinus problem you' re experiencing. A deficiency of essential fats will also make you more sensitive to allergens, so eat oily fish - sardines, mackerel, herring, trout or organic or wild salmon - three times a week, add pumpkin seeds, sunflower seeds and flax seeds to your breakfast every day, and supplement 1,000mg of fish oil or an omega-3/omega-6 blend twice daily.