Ono Mariko, Nagatomo Yoko, Kinoshita Hayato, Takeda Yukihisa, Nakamura Hiroyuki, Aoshiba Kazutetsu
Department of Respiratory Medicine, Tokyo Medical University Ibaraki Medical Center, Ibaraki, Japan.
Department of Respiratory Medicine, Tokyo Medical University, Tokyo, Japan.
Oxf Med Case Reports. 2021 Oct 26;2021(10):omab100. doi: 10.1093/omcr/omab100. eCollection 2021 Oct.
Acute respiratory illnesses that presented with diffuse ground-glass opacities (GGOs) on chest computed tomography (CT) scan suggest the diagnosis of coronavirus disease 2019 (COVID-19). However, many other diseases show similar CT findings, which often offer a difficult differential diagnosis. Here, we report a case of humidifier lung, a rare phenotype of hypersensitivity pneumonitis (HP), which mimicked COVID-19. A 71-year-old man was admitted because of dyspnea and diffuse GGOs found on chest CT scan. Although COVID-19 was initially suspected, his symptoms rapidly improved by the next day. A medical interview revealed that he had started using an ultrasonic humidifier 1 month ago. A high-resolution CT (HRCT) scan showed ill-defined centrilobular nodules and mosaic attenuation, which are typical of HP but atypical of COVID-19. The inhalation challenge test confirmed the diagnosis of humidifier lung. History-taking of humidifier use and a precise HRCT interpretation are helpful to differentiate it from COVID-19.
胸部计算机断层扫描（CT）显示为弥漫性磨玻璃影（GGO）的急性呼吸道疾病提示可能为2019冠状病毒病（COVID-19）。然而，许多其他疾病也有类似的CT表现，这常常导致鉴别诊断困难。在此，我们报告一例加湿器肺病例，这是一种罕见的超敏性肺炎（HP）表型，其表现酷似COVID-19。一名71岁男性因呼吸困难入院，胸部CT扫描发现弥漫性GGO。尽管最初怀疑为COVID-19，但他的症状在第二天迅速改善。病史询问显示，他1个月前开始使用超声波加湿器。高分辨率CT（HRCT）扫描显示边界不清的小叶中心结节和马赛克样衰减，这是HP的典型表现，但不是COVID-19的典型表现。吸入激发试验确诊为加湿器肺。询问加湿器使用史并进行精确的HRCT解读有助于将其与COVID-19区分开来。
