Changes of atopy prevalence among asthmatics visiting tertiary referral hospital (1983, 1990, 1997)

Park, Heung Woo; Kim, Sang Heon; Kim, Sang Hoon; Chang, Yoon Hae; Chung, Hee; Lee, Byung Jae; Kim, Yoon Keun; Cho, Sang Heon; Min, Kyung Up; Kim, You Young

Abstract

BACKGROUND: The prevalence of atopy and atopy-related disease has been known to increase during the past decade.
OBJECTIVE
This study was designed to evaluate the changes of atopy prevalence among asthmatic patients and the causative allergens. METHOD: A total of 698 asthmatic patients visiting Seoul National University Hospital in 1983, 1990 and 1997 was recruited. Skin prick test with common inhalant allergens was carried out and interpreted as positive when the mean wheal size formed by allergen was larger than 3mm. Atopy was defined when skin reaction to one or more allegens was positive. RESULT: The prevalence of atopy among asthmatic patients was 54% in 1983, 48.8% in 1990 and 53% in 1997, respectively. The prevalence of atopy decreased as the age of patients increased. Recently, old asthmatic patients (>55 years) showed a higher tendency to visit the tertiary referral hospital. When the data were analyzed according to age, the prevalence of atopy significantly increased among asthmatic patients aged 15-35 years, in whom the prevalence was 60.4% in 1983 and 81.3% in 1997 (p<0.05). The positive rate of skin test to Dermatophagoides pteronyssinus, cat fur, mugwort, ragweed, and grass pollen were significantly higher in 1997 than in 1983 (p<0.05).
CONCLUSION
The prevalence of atopy among asthmatic patients aged 15-35 years showed significant increase in 1997 compared to 1983. The changes of skin response to Dermatophagoides pteronyssinus, cat fur, mugwort, ragweed, and grass pollen contributed to the increase of atopy.