[Skin tests in asthmatic patients in Taiwan]

During the 22-year period from February, 1961 to December, 1982, 3550 asthmatic patients who visited the Taipei Municipal Chung-shing Hospital were skin tested with 35 allergens. The following results were obtained: The patients showed high skin reactivity to only inhaled allergens with positive rates in the order of 90.2% for house dust, 79.9% for candida, 73.0% for alternaria, 71.7% for aspergillus, 65.5% for cladosporium, 58.4% for tatami, 54.5% for penicillum and 52.3% for ragweed. While the sex had no influence on the incidence of skin test positivity, the positive rate peaked at around 20 to 30 years of age and decreased gradually thereafter. There was a significant correlation between PK titer and antigen threshold (r = +0.68). Although the healthy controls also showed positive skin reaction to house dust, none of them had an antigen threshold of higher than 16 (i.e. 16,000 X final dilution). Therefore an antigen threshold of 16 was suggested to be used as the cut point for the diagnosis of house dust allergen.