Corticosteroid resistance in chronic asthma.

Fifty-eight patients with chronic asthma in whom airflow obstruction was relieved by bronchodilator aerosols but not by oral corticosteroids were compared with 58 other chronic asthmatics who responded equally well to both treatments. The two groups were matched for age and sex. The only significant clinical differences between the two groups were that in the "corticosteroid-resistant" patients there was a more frequent family history of asthma and a longer duration of symptoms. Resistant patients also had a relatively lower peak expiratory flow rate in the morning than later in the day and a greater degree of bronchial reactivity to methacholine. Such features, however, may not be specific criteria of corticosteroid resistance since they were also observed in untreated asthmatics who subsequently responded well to corticosteroids. The failure of prednisolone to inhibit a monocyte-mediated bronchial reaction may explain why some chronic asthmatics do not respond to corticosteroids. Patients with corticosteroid-resistant asthma should be recognised at an early stage so that regular treatment with oral corticosteroids may be withdrawn. Failure to do this results in needless exposure to the risk of developing serious side effects.