Duration and specificity of sodium cromolyn on allergen inhalation challenges in asthmatics

In order to elucidate the mechanism of sodium cromolyn (Intal)^* ₁ > 20 per cent following allergen inhalation challenge were used in this experiment. Twelve patients were given 40 mg. disodium cromoglycate (DSCG) and then challenged on different days with allergen aerosol at 30 minutes, 5 hours, and 24 hours post-DSCG inhalation. Ten patients received one allergen 30 minutes post-DSCG and were challenged with the same or a dissimilar allergen 5 hours later. Protection against allergen-induced bronchoconstriction was significant at 30 minutes and 5 hours (p <0.001), but not at 24 hours. Bronchial protection with DSCG occurred during sequential allergen challenge using the same but not dissimilar allergens. DSCG protected against delayed reactions following allergen challenge, (p <0.01). The protection against the same allergen given twice, but not against a different allergen at 5 hours, suggests a mechanism of action of specific desensitization of the bronchial mast cells.