Natural history of asthma in patients requiring long-term systemic corticosteroids.

To study the natural history of corticosteroid-dependent asthma, we evaluated 40 randomly selected adult patients with severe asthma who were refractory to management with inhaled corticosteroids and bronchodilators and who required long-term prednisone therapy (mean duration, 6.2 +/- 5.1 years). During long-term observation, 13 patients (32.5%) significantly improved; ten (25%) of these tolerated discontinuation of long-term prednisone use and three (7.5%) had decreased prednisone requirements. Three patients (7.5%) had increased requirements for prednisone. Twenty-four patients (60%) had generally unchanged, long-term prednisone requirements; of note, eight of these had significant, but temporary intervals (mean, 3.2 years) when they could be managed without prednisone. Patients with mixed asthma were more likely to tolerate discontinuation of long-term prednisone; no other factors studied were predictive of the course of asthma. Although prior to our care many patients had a history of numerous emergency room visits and hospitalizations (some for life-threatening episodes of status asthmaticus), there were few emergency room visits and hospitalizations while under strict management by our service. Variations observed in the natural history of corticosteroid requirements in asthma must be considered in designing studies seeking to evaluate efficacy of new experimental therapies for asthma.