May 2020: Is It Always COVID-19 No Matter What?

Francesco Livrieri,1 Giulia Ghidoni,1 Roberto Piro,1 Francesco Menzella,1 Alberto Cavazza,2 Claudia Lazzaretti,3 Marco Massari,3 Gloria Montanari,1 Matteo Fontana,1 Nicola Cosimo Facciolongo1 1Department of Medical Specialties, Pneumology Unit, Arcispedale Santa Maria Nuova, Azienda USL di Reggio Emilia- IRCCS, Reggio Emilia 42123, Italy; 2Pathology Unit, Azienda USL/IRCCS di Reggio Emilia, Reggio Emilia 42100, Italy; 3Infectious Diseases, Azienda Unità Sanitaria Locale, IRCCS di Reggio Emilia, Reggio Emilia, ItalyCorrespondence: Francesco LivrieriDepartment of Medical Specialties, Pneumology Unit, Arcispedale Santa Maria Nuova, Azienda USL di Reggio Emilia- IRCCS, Reggio Emilia 42123, ItalyEmail francesco.livrieri@ausl.re.itAbstract: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing a massive outbreak throughout the world. In this period, diseases other than coronavirus disease (COVID-19) have not disappeared; however, it is hard for doctors to diagnose diseases that can mimic the clinical, radiological, and laboratory features of COVID-19, especially rare lung diseases such as acute eosinophilic pneumonia (AEP). We report the clinical case of a young patient who presented to the Emergency Department with respiratory failure and clinical symptoms, radiological aspects, and blood tests compatible with COVID-19; two swabs and a serology test for SARS-CoV-2 were performed, both resulted negative, but the respiratory failure worsened. Peripheral eosinophilia guided us to consider the possibility of a rare disease such as AEP, even if radiology findings were not pathognomonic. Therefore, we decided to perform a flexible bronchoscopy with bronchoalveolar lavage (BAL) at the lingula, which showed the presence of eosinophilia greater than 40%. As a consequence, we treated the patient with high-dose corticosteroids that completely resolved the respiratory symptoms. This case report highlights the difficulty of making alternative diagnoses during the COVID-19 pandemic, especially for rare lung diseases such as AEP, which may have initial characteristics similar to COVID-19.Keywords: COVID-19, acute eosinophilic pneumonia, bronchoalveolar lavage, ground glass opacities