*****FROM ABC NEWS MEDICAL UNIT*****
Hi chuckf11 and thank you for your question. Here's an answer from David Golden, M.D., Associate Professor, Div. of Allergy and Clinical Immunology, Johns Hopkins University:
Sinusitis can develop when there is swelling and congestion of the mucus membranes in the nose and sinuses. This causes blockage of the sinus passages and leads to a build up of pressure or infection inside the sinuses. The swelling and congestion that leads to sinusitis can be caused by allergic or non-allergic factors. Pollen allergies can lead to a flare-up of sinusitis. Prolonged (chronic) allergic congestion can lead to chronic sinusitis. There are often non-allergic factors that play a big roil, including viruses, weather and temperature changes, or irritating exposures such as smoke and fumes. Bug bites and stings do not cause a reaction of the nose or sinus membranes, so they do not lead to sinusitis.