Eosinophilic nonallergic rhinitis (ENAR), also known as nonallergic rhinitis with eosinophilia syndrome (NARES), is a hyperreactive nasal disease characterized by an increase in eosinophils in nasal secretions.

bubble_chart Pathological Changes

The etiology of this disease remains unclear. Wayof (1991) speculated that it might be an early manifestation of aspirin intolerance syndrome. It has been confirmed that eosinophil degranulation releases two cytotoxic substances: major basic protein (MBP) and eosinophil cationic protein (ECP). Both MBP and ECP can damage the mucosal epithelial cells, causing varying degrees of epithelial injury. As a result, nerve endings become more susceptible to stimulation, leading to heightened nasal reactivity. This suggests that the clinical symptoms of NARES are closely related to eosinophilia. Treatment with adrenal corticosteroids significantly reduces or eliminates eosinophils in nasal secretions, and clinical symptoms can also be controlled. However, treatment with sodium cromoglycate is ineffective.

bubble_chart Clinical Manifestations

Similar to vasomotor rhinitis and allergic rhinitis, patients often find it difficult to identify the triggers of symptom onset. Nasal examination also shows no characteristic changes, but a smear of nasal secretions may reveal a large number of eosinophils, and allergen skin tests are negative.

bubble_chart Diagnosis

The diagnosis of this disease can be made when there is an increase in eosinophils in nasal secretions without evidence of allergic reactions, presenting with symptoms of hyperreactive nasal diseases.

bubble_chart Treatment Measures

The main treatment is the intranasal application of topical corticosteroid preparations. Both beclomethasone dipropionate aerosol and triamcinolone acetonide nasal drops can be used.