Agreement rate of skin prick test with tissue eosinophil count in patients with nasal polyps

The pathogenetic mechanism of nasal polyps remains unknown, although allergy has been cited as an important factor in the etiology of nasal polyposis. Currently there is no definite histological criterion for differentiation of allergic from inflammatory nasal polyp. However, in a few studies, tissue eosinophil count has been used for this. This study aimed to find out the agreement rate of skin prick test and tissue eosinophil count in patients with nasal polyposis. Twenty five patients (18 males, 7 females) with nasal polyp were enrolled in this study. For each patient tissue sample from polyp material was taken for histopathological investigation. Moreover, skin prick test was performed for each patient using eleven common aeroallergens. Skin prick test was positive in 48% of the patients. Tissue eosinophil count of more than 50% was found in 75% of skin prick positive and in 69.2% of skin prick negative patients. Also tissue eosinophil count of more than 50% was found in 69.2% of patients with typical allergic symptoms as well as 75% of patients without allergic symptoms. No agreement was found between skin prick tests and tissue eosinophil counts in patients with nasal polyp. Also no difference was found between the tissue eosinophil counts in allergic and non allergic patients. Considering these results, it can be concluded that having a high tissue eosinophil count in patients with nasal polyp does not indicate that the polyp is allergic.