Severe chronic cough relating to post-COVID-19 interstitial lung disease: a case report.

Cough is a common symptom occurring in patients with acute coronavirus disease 2019 (COVID-19) infection as well as during the post-COVID-19 period. The post-COVID-19 cough can improve over time and the incidence of sustained post-COVID-19 chronic cough is low. Approaching post-COVID-19 cough is challenging to clinicians including pulmonologists and allergists due to a diverse set of etiologies and the lack of published guidance on effective treatments. A 60-year-old male ex-smoker presented to the outpatient long COVID-19 clinic because of a prolonged cough for 4 months after a severe COVID-19 infection. His cough was so violent that he had suffered a spontaneous pneumothorax on 2 occasions. In addition, he also complained of exertional breathlessness. Due to concerns over ongoing systemic inflammation from COVID-19 or thromboembolism, a serum C-reactive protein and d-dimer where checked and were normal. Chest computed tomography (CT) images revealed diffuse ground glass opacities combined with scattered emphysema in the bilateral upper lobes and several small bullae located close to the pleura. His diagnosis was post-COVID-19 interstitial lung disease (ILD) and he was treated with methylprednisolone 32 mg/day. After 2 weeks of treatment, he showed improvement with near cessation of cough and a significant decline in dyspnea. The follow-up chest CT also showed improvement in the ground glass opacities. Severe chronic cough could be a manifestation of post-COVID-19 ILD. This case demonstrates the use of systemic corticosteroid to improve both post-COVID-19 ILD and its associated chronic cough.