'''Extrinsic and intrinsic''' forms of the disease exist. The extrinsic form describes the formation of exudate in the airways and thickened airway walls. The intrinsic form describes the increased propensity for the bronchial smooth muscle to contract and lead to airway constriction. | '''Extrinsic and intrinsic''' forms of the disease exist. The extrinsic form describes the formation of exudate in the airways and thickened airway walls. The intrinsic form describes the increased propensity for the bronchial smooth muscle to contract and lead to airway constriction. |