Initial therapeutic dose of corticosteroid for an acute exacerbation of IPF is associated with subsequent early recurrence of another exacerbation.

Some patients with idiopathic pulmonary fibrosis (IPF) undergo recurrent acute exacerbations (AEs). This study aimed to elucidate the risk factors for recurrent AEs of IPF (AE-IPF). Consecutive patients with IPF admitted for their first AE-IPF between January 2008 and December 2018 were retrospectively recruited. Of 63 patients admitted for an AE-IPF and discharged alive, 9 (14.3%) developed a recurrence of AE within 1 year. The mean time to recurrence was 233 ± 103 days. Total doses (mg/month and mg/kg/month) of corticosteroids administered over day 1 to 30 after the AE were significantly higher in patients without recurrences of AE-IPF (5185 ± 2414 mg/month, 93.5 ± 44.0 mg/kg/month) than the doses in patients with recurrences (3133 ± 1990 mg/month, 57.2 ± 37.7 mg/kg/month) (p = 0.02 and p = 0.03, respectively). However, no differences were observed between the total doses of corticosteroids administered over days 31 to 60, 61 to 90, 91 to 120, and 151 to 180 after the AE. Furthermore, differences between the administration rates of immunosuppressive and antifibrotic treatments administered to the 2 patient groups were not significant. An increased total dose of corticosteroid administered over day 1 to 30 after an AE-IPF was associated with a decreased risk of subsequent recurrence of AE-IPF within 1 year after the first AE.