Nasal polyposis: a study of its association with airborne allergen hypersensitivity

Background: Despite the frequent presence of clinical symptoms such as snee zing and itching, elevated histamine and IgE in extracellular polyp fluids, tissue eosinophilia, and degranulated mast cells, allergy is not considere d an important cause of nasal polyposis. Objective: To investigate the prevalence of immediate skin reactivity to ai rborne allergens in patients with nasal polyposis. Methods. Sixty-eight patients with nasal polyposis and 36 controls with chr onic sinusitis were submitted to skin prick tests (SPTs) with a large serie s of seasonal and perennial airborne allergens including: grass, mugwort, r agweed, pellitory, plantain, birch, hazel, olive, cypress, house dust mites , cat and dog dander, and thirteen molds (Alternaria, Aspergillus, Cladospo rium, Penicillium, Candida, Trichophyton, Fusarium, Curvularia, Botrytis, P ullularia, Rhizopus, Mucor, Helminthosporium). Results: Forty-three of 68 (63%) patients with nasal polyposis versus 6 of 35 (17%) controls were positive on SPT with airborne allergens (P < .001). A comparison with 1,128 subjects with respiratory allergy seen from 1996 to 1999 showed a markedly higher prevalence of sensitivity to Candida albican s (19 of 43 [44%] vs 8 of 1,128 [1%]; P < .001) and to house dust mites (12 of 43 [28%] vs 154 of 1,128 [14%]; P < .05) among allergic patients with p olyps. Altogether, 30 of 43 (70%) patients versus 215 of 1,128 (19%) contro ls were sensitive to at least one perennial airborne allergen tie, mold, mi te, or animal dander) on SPT (P (.001); in contrast, 26 of 43 (60%) patient s versus 942 of 1,128 (84%) controls were sensitive to seasonal airborne al lergens (P < .005). A review of the clinical histories of SPT-positive pati ents revealed the presence of obstructive rhinitis and chronic rhinorrhea o nly in most cases, whereas acute symptoms, such as sneezing and itching, we re reported only by a minority of subjects. Conclusions: A clinically slight respiratory allergy, particularly to peren nial airborne allergens, might play a relevant role in the pathogenesis of nasal polyposis, probably through the induction of a long-lasting inflammat ion of the nasal mucosa.