Which symptom is a major diagnostic criterion for chronic sinusitis?

Nasal obstruction is a major diagnostic criterion for chronic sinusitis because it reflects the underlying inflammation and blockage of the sinus passages that characterizes the condition. Chronic sinusitis is often associated with persistent symptoms lasting more than 12 weeks, and nasal obstruction occurs as a result of mucosal swelling and thick mucus production, which impede the normal drainage of the sinuses.

This obstruction can lead to a sensation of pressure in the face, difficulty breathing through the nose, and can sometimes exacerbate other symptoms like cough and post-nasal drip. The prominence of nasal obstruction in the diagnostic guidelines underscores its significance in distinguishing chronic sinusitis from other respiratory conditions that may not present this symptom as predominantly.

In contrast, fever, cough, and sore throat are more nonspecific symptoms that could be associated with a range of upper respiratory conditions, but they are not definitive criteria for diagnosing chronic sinusitis. This focus on nasal obstruction helps clinicians ascertain the presence of chronic inflammation and blockage specific to sinus issues.