Immunopathology of nasal polypi

THE aetiology of nasal polypi remains an unsolved enigma (Lederer, i960). A local irritation such as allergy or infection is often incriminated as the primary stimulus. Inflammation and atopy may be present together, aiding and abetting each other. The associated periphlebitis and lymphangitis result in obstruction of the venous and lymphatic flow with resultant oedema and hypertrophy of the tissue leading to polyp formation. The polyp may act as a 'dialysis sac', with the evaporation of water from the mucosa permitting concentration of proteins inside. The role of local allergy is suggested by the presence of eosinophils in the blood, nasal secretions and the polyp, the demonstration of a high concentration of reagin in the polyp fluid by passive transfer experiments, and positive skin tests with specific allergens. Smith (10,71) suggested that an alteration in carbohydrate metabolism and deposition of a short-chain hydrophilic polysaccharide may play a significant role in the pathogenesis of the fibromyxomatous polyp, especially in patients without a definite history of inhalant allergy or positive skin reactions.