ABSTRACT
Allergic nasal polyposis is an agonizing problem in the practice of otorhinolaryngology. The exact etiology and pathogenesis are still a matter of controversy. The present work aimed to clarify the sequence of events in the pathogenesis of nasal allergy and to throw a light on the initiating factors that predispose to polypoidal formation. Nasal biopsies were taken from selected twenty male patients with allergic rhinitis [10 patients without polypi and 10 with polypi]. The associated polypus tissue was studied. Biopsies were taken also from five volunteers used as a control. Electron microscopic study of the allergic nasal mucosa showed thickening and metaplasia of the lining epithelium with thickening of their basement membrane. The lamina propria manifested cellular infiltration especially those of fibroblast, lymphocytes, plasma cells, macrophages and mast cells which depicted a degree of degranulation more in cases with polyposis. The glandular structures showed hyperactivity of the serous element with loss of their microvilli and cilia. Zymogen granules appeared more numerous and of more electron density. There was increased vasculature with hypertrophy and gaping of the endothelial lining cells and thickening of the basal lamina of blood capillaries. Polypus tissue showed a structure similar to that of allergic nasal mucosa. Their epithelial cells were widely separated and the stroma was edematous. The vasculature and glandular elements were greatly reduced. The ultrastructural changes in allergic rhinitis with elements were greatly reduced. The ultrastructural changes in allergic rhinitis with and without polyposis were more or less the same. The changes were more marked in cases with polyposis. This might be due to difference in the degree of tissue reaction to allergen which may be due to the variability in the initial site that provoke it