Sinusitis is a confusing topic, not only for patients but for many health practitioners as well. The confusion arises because of the many facets of this condition, problems with establishing the cause, and similarities between the symptoms of infection and those of allergy. In many cases allergy and infection coexist, feeding on each other, so that the allergic reaction also provides a home for micro-organisms and any infection (and its treatment) can trigger an allergic reaction.
Over-use of antibiotics and cortisone sprays has led to more virulent forms of bacterial infections as well as new fungal infections of the sinus cavities. Asthma and allergic disorders often cause chronic inflammation of the nasal mucosa, resulting in chronic sinusitis. About 20% of patients with chronic sinusitis may develop nasal polyps, cyst-like growths that develop from sinus tissue and may further obstruct the sinuses.