Post-steroid rebound in COVID-19 pneumonitis: a case series and review of the literature.

We report a retrospective case series of COVID-19 pneumonitis (C19P) patients in hypoxic respiratory failure who experienced a symptom rebound upon cessation or weaning of steroids following an initial positive response. The post-steroid rebound phenomenon in C19P is not well described in the literature and we aim to add to the body of evidence exploring this pathology.

Methods: Post-steroid rebound COVID-19 pneumonitis (PSRCP) cases at our institution were identified for notes review from respiratory department follow-up records. The inclusion criteria were as follows: 1. Hospital admissions with radiologically and PCR-confirmed C19P. 2. Administration of a corticosteroid course for the indication of hypoxia due to C19P. 3. An objective relapse of the index presentation with differential diagnoses other than post-steroid rebound excluded by appropriate clinicians. A literature search was performed using Medline, Ovid and Google Scholar and the search terms "rebound and COVID-19", "rebound and COVID-19 and pneumonitis" "post-COVID and pneumonitis" "relapse and COVID-19", "relapse and coronavirus and pneumonitis".

Results: Eighteen patients were identified between 2021 and 2024 with ages ranging from 48 to 80 years. The most common comorbidities were hypertension (50%) and obesity (39%) while 89% had a history of regular smoking. Seventeen of the 18 had evidence of hyperinflammation at first C19P presentation with a C-reactive protein (CRP) ≥ 75 mg/dl. Notably, 15 patients had a CRP blood test at least 48 h prior to discharge, steroid cessation or weaning and of these, 11 (73%) showed persisting CRP elevation. Seventeen of the 18 responded upon diagnosis of PSRCP to steroid rechallenge with survival to discharge.

Conclusions: As COVID-19 becomes endemic, clinicians should remain wary of the risk of PSRCP. Greater recognition of the importance of steroid weans and rechallenges in C19P narratives will help avoid poor outcomes, readmissions and the risk of post-C19P sequelae. Awareness of the PSRCP phenomenon should lower the threshold for slow steroid weans upon an initial C19P diagnosis over the standard UK regimen of a 10-day duration or less dexamethasone course. A definition for PSRCP is proposed as well as a decision aid around steroid strategies in patients both with and at risk of PSRCP.