Background: Randomized controlled trials are needed to evaluate the effects of complementary treatments in asthma. This study assessed the effect of salt chamber treatment as an add-on therapy to low to moderate inhaled steroid therapy in asthma patients with bronchial hyperresponsiveness (BHR).
Methods: After a 2-week baseline period, 32 asthma patients who exhibited BHR in the histamine inhalation challenge were randomized: 17 to 2-week active treatment, during which salt was fed to the room by a salt generator, and 15 to placebo. The salt chamber treatment lasted 40 min and was administered five times a week.
Results: Median provocative dose causing a decrease of 15% in Fev1 (PD15FEV4) increased significantly in the active group (P = 0.047) but not in the placebo group. The difference in changes between the active and placebo groups was significant (P = 0.02). Nine patients (56%) in the active group and two patients (17%) in the placebo group exhibited at least one doubling dose decrease in BHR (P = 0.040). Six patients (38%) in the active group and none in the placebo group became non-hyperresponsive (P = 0.017). Neither the peak expiratory flow (PEF) values measured just before and after the treatment, nor FEV1 values measured before the histamine challenges, changed. The reduction in BHR was not caused by changes in the baseline lung function.
Conclusions: Salt chamber treatment reduced bronchial hyperresponsiveness as an add-on therapy in asthmatics with a low to moderate dose of inhaled steroids. The possibility that salt chamber treatment could serve as a complementary therapy to conventional medication cannot be excluded.