Clinical trial, with positive findings,  conducted on 24 patients attending an asthma outpatient clinic in  Scotland; most of them were sensitive to house-dust mite. Approximately  half of the patients were randomly allocated to receive homeopathic  immunotherapy to their principal allergen; the others received a dummy  medicine (placebo). They did not know which treatment group they were  in. After 4 weeks, the patients who received homeopathic immunotherapy  reported milder asthma symptoms overall than those who received placebo.

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