Sinusitis is inflammation of the nasal cavity and the sinuses, which are air-filled spaces located primarily in the jaw above the upper teeth and in the forehead around the eyes.

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The sinuses consist of four symmetrical sets of air-filled bony cavities located in the forehead and cheeks and adjacent to the nose.

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But what causes one person to become sensitive to these indiscriminate antigens floating through the air, while another sails through life with dry eyes and clear sinuses?

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