Steeple sign and narrowed upper airway in an influenza patient

Excerpt

A 61-year-old previously healthy man presented with fever, cough, and acute-onset dyspnea. On arrival, stridor was heard around his neck, and his breathing pattern seemed distressed. Body temperature was 38.5 °C; respiration rate, 32/min; SpO₂, 90% (room air). Laboratory data was non-specific except for an elevated leukocyte count of 13,800/µL, and positive rapid antigen test result for the influenza A virus. His chest X-ray showed no consolidation in the lung fields, but the steeple sign—indicating a narrowed upper airway—was identified (Fig. 1). A computed tomography (CT) scan showed a normal epiglottis and swollen tissue around the vocal cords (Fig. 2). He was diagnosed with croup, secondary to acute laryngitis, caused by influenza virus. Influenza virus can cause croup at any age, especially during its annual epidemic season. A simple chest X-ray finding can contribute to the early detection of upper respiratory problems and deteriorating clinical condition.

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