The Etiology of Chronic Rhinosinusitis Remains Unclear

Osteitis, or inflammation of the bone, can generate bacteria that interfere with the mucosal surface in the paranasal cavities, leading to CNS, said Dr. Bernstein.

Another cause of CNS may be the overuse of antibiotics by general physicians, said Dr. Bernstein. Antibiotics may kill good bacteria, allowing more pathogenic types to grow in the paranasal cavities, he explained.

Genetics may also provide some answers to the etiology of the disease. Dr. Bernstein and his colleagues are collecting buccal swabs from CRS patients with paranasal polyps to determine if a genetic cause exists. We’re working on isolating single nucleotide polymorphisms that are responsible for proinflammatory cytokines, he said. This discovery may help answer why polyps recur in some patients even after they undergo surgery. IL-1 beta at +3945 position may have an altered nucleotide at that position, which may upregulate the synthesis of that proinflammatory cytokine protein, he said.

Post-surgical inflammation, environmental triggers, allergens, and cilia dysfunction often also contribute to the disease, said Dr. Palmer.

Additionally, a patient’s immune system is very sensitive to external triggers, including environmental allergens, climate, and psychological/mental stresses, and may contribute to CRS, noted Dr. Wang.

Treatment Implications

Inflammation associated with CRS can have many causes; however, end-stage treatment of the disease is usually the same, said Dr. Palmer. Generally, physicians use sinus surgery and a variety of medications to treat CRS.

Functional endoscopic sinus surgery may help get rid of limited CRS, said Dr. Bernstein. However, if the patient has hyperplastic disease with nasal polyps, surgery alone won’t help. You have to remove the chronic disease and provide thorough postoperative care, which includes cleaning and medication, he said.

Helpful agents may include oral or topical steroids and anti-inflammatory drugs, he said, adding that erythromycin is often used as an anti-inflammatory rather than an antibiotic.

Overall, the various causes of CRS make it harder for antibiotics only to cure certain cases, said Dr. Ramada.

If it was only bacterial, people receiving antibiotics would be more readily able to rid themselves of the condition, said Dr. Palmer.

In addition, because biofilms are so large, they may be difficult to eradicate with antibiotics it they are the cause of disease, noted Dr. Bernstein.

Other medications for CRS include leukotriene antagonists, which help block airway constriction and mucus production, and topical diuretics such as amiloride, which block sodium channels and decrease swelling, said Dr. Bernstein.

In general, after patients undergo treatment, they can experience three to five years without a major recurrence, he added.