# An Uncommon Case of Secondary Organizing Pneumonia Due to Influenza A Infection

## TL;DR

A 62-year-old woman developed secondary organizing pneumonia after an influenza A infection, highlighting the importance of recognizing this rare complication.

## Contribution

This case report highlights the rare occurrence of secondary organizing pneumonia following H1N1 influenza A infection and emphasizes the need for vigilance in diagnosis.

## Key findings

- A 62-year-old woman with confirmed H1N1 influenza A developed secondary organizing pneumonia.
- Standard antiviral therapy was insufficient, requiring methylprednisolone pulse therapy for improvement.
- The case underscores the importance of considering organizing pneumonia in patients with persistent symptoms after viral pneumonia.

## Abstract

Secondary organizing pneumonia (SOP) is defined as a lung disease process caused by pulmonary tissue injury. SOP may rarely occur after influenza A infections, including H1N1 influenza A. We present a case of a 62-year-old woman who was diagnosed with viral pneumonia caused by type A influenza, which was confirmed by nasopharyngeal swab reverse transcription-polymerase chain reaction (RT-PCR). Her abnormal chest shadows and oxygen demand did not improve despite antiviral therapy. Given her clinical deterioration, a high-resolution CT of the chest (HRCT-chest) was done, which confirmed SOP. She was managed with methylprednisolone pulse therapy followed by a tapering regime in addition to standard treatment. This report underscores the need for physicians to remain vigilant about the possibility of OP even in cases of viral pneumonia.