Differential diagnosis of chronic nasal inflammation is insufficient when based solely on clinical examination and radiography of paranasal sinuses. Activation of mast cells and eosinophils is pivotal in nasal inflammation. Objective was to compare tryptase and ECP in nasal secretions between different forms of chronic nasal inflammation.

The study included 1,710 patients presenting with nasal complaints. Nasal secretions were gained by the cotton wool method and analyzed for tryptase, as a marker of mast cell activation, and for ECP, as a marker of tissue eosinophilia. Patients were grouped according to their diagnosis: chronic, non-allergic rhinosinusitis (sinusitis, n=194), non-allergic nasal polyposis (polyposis, n=138), Non-Allergic Rhinitis with Eosinophilia Syndrome (NARES, n=198), isolated perennial allergic rhinitis (AR) (n=126), isolated seasonal AR (n=132), and patients allergic to both, seasonal and perennial allergens (n=193). 729 healthy subjects with nasal complaints due to a deviated septum and without any nasal inflammation served as controls.

Nasal tryptase was highly significantly (P<.001) elevated in polyposis, NARES, and in AR. ECP was highly significantly (P<.001) elevated in all groups of patients suffering from chronic nasal inflammation. Based on our data and method we established norm values (95% confidence interval of mean value) for nasal tryptase in healthy adults ranging from 12.0 to 18.7 ng/ml and for ECP ranging from 84.4 to 102.6 ng/ml.

Mast cells and eosinophils are involved in non-allergic and allergic forms of chronic nasal inflammation. We established an in-vitro assay for tryptase and ECP in nasal secretions and defined norm values based on our data and method.