Asthma from diisocyanates is not mediated through a Type IV, patch-test-positive mechanism.

ABSTRACT

The mechanism of occupational asthma from diisocyanates (DI)(1-10)(Fig. 1) is not fully known; only about 10%-30% of such patients have specific IgE antibodies to DI (3, 11, 12). A T-cell mediated response has been considered to be involved in DI asthma (13) and we therefore wondered whether patch testing might be of any help in its diagnosis.