Although asthma is a heterogeneous disease, all individual with asthma would be most likely to:'

Demonstrate nonspecific airway hyperirritability. The impoance of immune mechanisms in the pathogenesis of asthma is suggested by the common association between the disease and the presence of allergic diseases, skin-test sensitivity, and increased serum IgE levels. In addition, many susceptible persons develop bronchospasm after inhalation challenge with airborne allergens. A large propoion of asthmatic subjects, however, have none of these markers of immunologic activity and are classified as having idiosyncratic asthma. When tested for bronchial hyperirritability with various nonantigenic bronchoprovocational agents (e.g., histamine and cold air), asthmatic subjects are found to be more sensitive than normal, and the bronchoconstriction is generally reversible after exposure to a j3-adrenergic agonist; the reason for this airway hyperirritability, which is a common feature in all asthmatic persons, is unlmown. Although psychological factors ceainly influence the expression of asthma, no single personality type is considered "asthmatic".