Results
All patients included in the study were considered to have moderately severe asthma because they required regular bronchodilator therapy together with inhaled beclomethasone or sodium cromoglycate to remain symptom-free. Except for one, PC20 of all patients on the control day was less than 1.0 mg (Table 1). No patient prior to the study had evidence of airflow obstruction and Deo measurements of all patients were normal. The age of onset of asthma ranged from birth to 55 years of age. Comparison of basal FEVj values on the three study days showed no significant differences and the basal pulmonary function status of patients was similar on the three study days (Table 2). Comparison of PC20 on the control day with those seen after real and placebo acupuncture were also not statistically different (Table 3). There was no significant difference in the PC20 following real acupuncture and that following placebo acupuncture. All patients tolerated acupuncture well, apart from one child who developed a transient fainting sensation. further

Discussion
Inhalation tests with histamine give a sensitive indication of bronchial hyperreactivity. Increased bronchial reactivity to histamine is an abnormality seen in active asthmatic subjects, and Charpin et al have indicated that in France it is included as a part of the definition of asthma. Increased bronchial reactivity to histamine has been shown to have a close parallel with the overall severity of asthma as indicated by the usual drug requirements for optimum symptom control. Patients with PC20 under 1 mg are classed as having moderately severe asthma, as included in this study, and have been shown to require treatment with bronchodilators on a regular basis with or without additional corticosteroids.
Bronchial hyperreactivity to histamine was used in this study to evaluate the effectiveness of acupuncture on modulating the underlying asthma status because this approach was considered to be a reliable method of determining whether or not the acupuncture would affect the underlying asthma. Any changes in bronchial hyperreactivity to histamine would have to be due to a change in the bronchial smooth muscle reactivity rather than due to any environmental changes because all patients were studied during a stable phase and within a short period of time with stable lung function.
Table 2—Basal Lung Function Results of Three Study Days

MeanDifference SD PValue
Control day FEV,2.15*(1.14-3.4)t Real Acupuncture day FEV,2.23*(l.l-3.3)t 0.0737 0.245 >0.05
Control day FEVi Placebo Acupuncture day 2.27*(1.19-3.76)1* 0.113 0.352 >0.05

Table 3—Comparison PC20 Histamine Doses

MeanDifference SD PValue
Control Real Acupuncture 0.11 + 0.262 >0.05
0.382* 0.273*
Control Placebo 0.0122 + 0.243 >0.05
0.382* 0.369*
Placebo Acupuncture— 0.0963 + 0.268 >0.05
Real Acupuncture