Although these organisms are abundant in the environment, they usually are harmless to healthy people, indicating that the human body has a natural resistance to them. Fungi, such as Aspergillus , can cause serious illness in people whose immune systems are not functioning properly. Some people with fungal sinusitis have an allergic-type reaction to the fungi. Patients with allergic rhinitis also often have chronic sinusitis. Vasomotor rhinitis , caused by humidity, cold air, alcohol, perfumes, and other environmental conditions, also may be complicated by sinus infections.
Acute sinusitis is much more common in certain patients than in the general population.
Chronic Sinusitis Chronic sinusitis refers to inflammation of the sinuses that continues for at least 3 weeks, but often continues for months or even years. As noted above, allergies are frequently associated with chronic sinusitis. Patients with asthma have a particularly high frequency of chronic sinusitis. Damp weather, especially in northern temperate climates, or pollutants in the air and in buildings also can affect people subject to chronic sinusitis. These latter patients have a high frequency of chronic sinusitis.