Asthma is a respiratory tract disease which usually affects the airways making breathing difficult. During allergic reactions, histamine is released from basophils. Histamine then binds to histaminic receptors(specifically, h6 receptors). The response to this binding is bronchoconstriction. Constricted bronchus usually affects forced expiratory volume measurements and sometimes respiratory minute rate.
NSAIDS block the cox-pathway and potentiates the lox-pathway. In the lox-pathway, LTB4 and LTD4 are produced. The latter which is produced is a potent bronchoconstrictor thus precipitating asthma. This explains why asthmatics are not to be given NSAIDS.
farewell, isn't it?