A middle-aged woman sought care for a sudden-onset dry cough lasting 3 months that didn't respond to inhalers or over-the-counter cough suppressants.

Despite unremarkable chest imaging, pulmonary function testing, and otolaryngologic assessment, the patient's cough worsened and disrupted sleep and daily activities. She also reported a persistent globus sensation, stress urinary incontinence related to coughing, and had a 20–pack-year smoking history.

Chest radiography and computed tomography of the neck and thorax demonstrated normal airway patency and lung parenchyma without structural abnormalities. Pulmonary function tests were within the reference ranges. Otolaryngologic assessment with flexible nasendoscopy showed normal bilateral vocal cord mobility and no mucosal lesions. Evaluation by speech and language therapy identified no abnormalities in breathing or voice, and a videofluoroscopic swallow study confirmed normal oropharyngeal and laryngeal movement with preserved airway protection.

Flexible bronchoscopy identified marked laryngeal hypersensitivity. Although the lower airways appeared normal, minimal contact with the larynx elicited repetitive coughing despite adequate sedation, consistent with marked laryngeal hypersensitivity. In the absence of alternative pathology, the researchers diagnosed cough-predominant laryngeal hypersensitivity syndrome.

Laryngeal hypersensitivity syndrome is a sensory disorder characterized by heightened responsiveness of the laryngeal cough reflex, often triggered by minimal mechanical or environmental stimuli. The symptoms can vary widely and may include a chronic cough, throat irritation, a globus sensation, or choking episodes, which can complicate diagnosis. Because routine imaging, pulmonary testing, and otolaryngologic examination are frequently normal, the condition may remain unrecognized without targeted evaluation. The researchers noted that flexible bronchoscopy can play a key role in identifying exaggerated laryngeal sensitivity when standard investigations fail to show an explanation for persistent cough.

Management emphasized conservative, multidisciplinary strategies, including patient education, hydration, behavioral cough suppression techniques, psychosocial support, and referral to a smoking cessation program.

“This case underscores the importance of considering laryngeal hypersensitivity syndrome in patients with unexplained chronic cough despite normal routine investigations,” noted lead study author Muhammad Ammar Iqbal, Fellow Physician, MBBS, of Respiratory Medicine at the University Hospital Limerick in Ireland, and colleagues.

The authors reported no conflict of interest.

Source: Cureus