Nasal allergy in medical students.

The incidence of nasal allergy in medical students was studied in our University from 1983 to 1987. Intradermal skin tests were performed using six allergens: house dust (HD), ragweed, Japanese cedar, orchard grass, candida and broncasma berna. 154 out of 471 students (32.7%) had symptoms indicative of nasal allergy. HD and Japanese cedar were the main allergens and their positive rates were 66.4% and 51.0%, respectively in symptomatic cases. However, 34.4% of asymptomatic students also showed positive reactions to HD and 19.6% to Japanese cedar. In nasal provocation tests, 53.8% of symptomatic students who reacted positively to HD skin test showed positive reactions, while even 34.8% of asymptomatic students also showed positive reactions. The same results were obtained for Japanese cedar. It seemed that some asymptomatic students who had positive reactions to skin tests have latent allergies. A long-term follow-up would be necessary for these cases.