An increase of the histamine threshold after treatment with antiallergic agents by more than eightfold or an increase of the threshold by more than 10,000 p.g/ ml was defined as improvement in bronchial hypersensitivity. proventil inhaler
Severity of asthmatic symptoms was evaluated in the month before the initial visit to our hospital and before each histamine inhalation challenge. Symptoms were classified into four grades; severe, moderate, mild, and symptom-free in accordance with the strength and the frequency of asthmatic attacks. “Symptom free” was defined as no asthmatic attacks in the one-month period before each test.

Statistics
Data are expressed as the mean ± SD. Statistical significance was evaluated by the Fishers exact probability test or Students f-test, and a p<0.05 level of significance was adopted throughout the study.

Results
Patients Characteristics in Hypersensitivity-Improved and -Unimproved Groups Treated with Antiallergic Agents
Improvement of bronchial hypersensitivity to histamine inhalation was observed in 11 out of 24 (46 percent) patients who were treated with antiallergic agents. As shown in Table 1, there was no significant difference in age, sex, type of asthma, type of drugs used, or administration periods between the two groups. However, it was found that the number of short-term cases was significantly higher in the improved group.

Table 1—Comparison of Patients’ Characteristics Between Bronchial Hypersensitivity-Improved and -Unimproved Groups Treated with Antiallergic Agents (n—24)

Croup No. of Patients Age, yr Age<50y:50y< M:F Antiallergic Agents (Cases) Administration Period, mo No. of Short-Term Cases Type of Asthma Extrin:Intrin
Improved 11 (46%) 35.2± 14.6 9:2 6:5 DSCG 8 Ibudilast 2 Repirinast 1 5.7 ±2.8 8/11 (73%) 5:6
Unimproved 13 (54%) 36.7 ±10.2 11:2 11:2 DSCG 8 Ibudilast 4 Tranilast 1 5.5±2.9 3/13 (23%) 7:6