Mucosal inflammation and bronchial hyperreactivity.

Asthma is a chronic disease characterized by increased bronchial responsiveness ranging in degree from mild ~o severe. AU:Way inflammation has been receiving 1ncrcased auenuon as the major mechanism in bronchial hypcrrcsponsiveness. Many stimuli known to induce airwa~ inflam~ation ~lso i.ncrease bronchial reactivity, e.g. v~ral rcsp1ratory mfectJOns, ozone, antigens and chem1ca ls such as toluene diisocyanate (TDI). ~nflamma~ion should be understood not only as an mcrease m the number of inflammatory cells, but also as including an increase in the bronchial blood flow and vascular permeability leading to mucosal oedema and epithelial shedding. The time sequence and severity of this inflammatory process in the pathogenesis of asthma is not known, although some information of the separate events has been obtained in recent studies (LAITINEN et al. [1]; BARNES [2]· PERssoN [3)) •