Serum IgE levels: correlation with skin test reactivity in Thai adults with respiratory allergy.

A history of respiratory allergic disorders was obtained in 68 patients. Allergic skin testing was performed with measurement of total IgE by enzyme immunoassay (EIA). The mean level of total IgE from the control group of 13 healthy adults with no history of allergic diseases was 24.7 IU per ml. The average serum IgE level among the allergic patients with positive skin tests was 97.6 IU per ml and it was significantly higher than that of the controls (p less than 0.005). It was also found that the positive skin test patients had significantly a higher mean serum IgE level than that of patients with negative skin test results (97.6 vs 33.6 IU per ml, p less than 0.01). Since 73.2% of the allergic patients with positive skin tests had serum IgE levels over 45 IU per ml while only 23.1% of the control group had IgE levels exceeding this figure, we consider that a patient with clinical symptoms and a serum IgE level over 45 IU per ml is likely to be suffering from allergic disease.