Spontaneous hydropneumothorax during the post-acute phase of COVID-19: a case report

Abstract Background Long COVID refers to symptoms that develop or persist beyond the acute phase of COVID-19 without any alternative explanation. It has been associated with a wide range of multisystem manifestations, including pleuropulmonary ones, although hydropneumothorax has rarely been reported in this setting. Here, we describe such an occurrence in a young woman during the post-acute phase of a mild infection. Case presentation A 21-year-old Iranian woman presented with dyspnea and pleuritic chest pain that had developed and worsened over the preceding week. Eight weeks earlier, she had had a mild COVID-19 infection, and these acute symptoms were superimposed on mild fatigue and an intermittent dry cough that had persisted since then. Breath sounds were reduced over the right hemithorax, and percussion showed dullness below and hyperresonance above, suggesting coexisting fluid and air, which was confirmed by a chest radiograph showing a right-sided hydropneumothorax. A chest tube was then placed, and pleural fluid analysis showed a lymphocyte-predominant exudate with no evidence of infection, tuberculosis, or malignancy. Further imaging revealed no structural, parenchymal, or vascular abnormality to account for the findings. After a six-day hospital stay, the lung re-expanded fully, the tube was removed, and the patient was discharged. The hydropneumothorax thus occurred at eight weeks, within the post-acute phase but before the twelve-week threshold for post-COVID-19 syndrome. The residual fatigue and cough resolved only about five months after the initial infection, a course subsequently meeting the criteria for post-COVID-19 syndrome. Conclusion Spontaneous hydropneumothorax is a rare but important consideration in patients presenting with new respiratory symptoms during the post-acute phase of COVID-19, once trauma, infection, malignancy, and underlying structural lung disease have been systematically evaluated. Careful physical examination may provide the first clue to early diagnosis.