Late Onset Post-COVID Fibrosis - A Case Report

Introduction: While most cases of COVID-19 recover completely within 2-6 weeks, some may develop complications including residual lung fibrosis. We describe an interesting case of late-onset post-COVID fibrosis that presented more than 4 months after the initial infection. Case: A 52-year-old male, an operating room technician by profession tested positive for COVID-19 after coming in contact with an infected patient early in May 2020. He was asymptomatic, vitally stable with no comorbidities, and was given a course of oral hydroxychloroquine, oseltamivir, and multivitamins. He remained asymptomatic for a week in the isolation ward with all investigations within normal range and was discharged home. HRCT thorax on the first follow-up at 2 weeks was normal and the patient resumed work as usual for the next 3 months. In mid-September, the patient presented to the outpatient clinic with a sudden onset of dyspnea on exertion that was progressive for 5 days with an oxygen saturation of 93% on room air. He was unable to perform a 6-minute walk test (6MWT). Spirometry was suggestive of moderate restriction and reduced DLCO. HRCT thorax at this point revealed bilateral extensive reticular opacities with few ground-glass opacities (GGO's) in all lobes bilaterally with a basal predominance. These findings were suggestive of late-onset of residual fibrosis more than 4 months after the initial infection. RT-PCR for COVID-19 was negative and ruled out re-infection. The patient was unwilling for admission and was started on oral pirfenidone, a tapering dose of oral prednisolone, and was advised home oxygen therapy. He did not take home oxygen but was compliant with oral steroids and antifibrotic. In the 7th-month of post-COVID follow-up, HRCT showed significant improvement as compared to the previous scan with reduced reticular opacities and minimal GGO's. The patient was symptomatically better with a saturation of 98% on room air and could perform 6MWT satisfactorily. Spirometry showed mild restriction and improvement in FVC. The antifibrotic dose was stepped up and the patient was referred for pulmonary rehabilitation. Discussion Despite an uncertain natural history of post-COVID sequelae, it has been observed that post-COVID fibrosis can develop as early as 3 weeks after the initial infection. This case was unique in its late presentation during the second post-COVID follow up at 4 months with normal imaging and clinical parameters during the first follow up. Hence a meticulous long-term follow-up should be done for all patients.