DOUBLE-BLIND TRIAL OF HOUSE-DUST MITE IMMUNOTHERAPY IN ASTHMATIC-CHILDREN RESIDENT AT HIGH-ALTITUDE

Twenty-three Dermatophagoides pteronyssinus (Dpt)-sensitive asthmatic children aged 7-14 years entered a double-blind, placebo-controlled tr ial of standardized immunotherapy (IT) (Alpare) while resident at high altitude. Dpt sensitivity was evaluated by skin prick tests at differ ent allergen concentrations at the enrollment and after 6 and 12 month s of treatment. Bronchial hyperreactivity was evaluated at the same ti me points, and on each occasion, histamine challenge and, the followin g day, Dpt bronchial challenge were performed. All patients, irrespect ive of active treatment, improved clinically and in lung function with increased PC20 and Dpt-PD20. Alpare-treated patients had a significan tly decreased sensitivity on Dpt skin testing (P < 0.009) and felt tha t their asthma had improved (P < 0.001) compared with placebo-treated subjects, but there was no difference between the treatment groups in lung function or bronchial challenge response. IT neither increased no r decreased bronchial histamine sensitivity. Our results indicate that Dpt IT benefits asthmatic children, but improvement by allergen avoid ance at high altitude is even greater.