Otolaryngologic Clinics of North America
Volume 43, Issue 1, Pages 111-121 (February 2010)
John H. Krouse, MD, PhDa, Kenneth W. Altman, MD, PhDb
Over the past 10 years, there has been increasing recognition of the interaction between the upper and lower airways in patients with a variety of infectious and inflammatory illnesses, including allergic rhinitis, rhinosinusitis, and asthma. Epidemiologic and mechanistic links have been proposed to demonstrate these relationships and to offer possible etiologic explanations to account for these observations. Among patients with upper respiratory illnesses, cough can be seen as a common symptom, both from the direct influences of upper airway inflammation, which incite reflex changes and bronchospasm, and from the exacerbation of associated pulmonary processes, such as asthma. Despite this increasing awareness of interaction between the upper and lower airways, the influence of both upstream and downstream respiratory inflammatory processes on laryngeal pathophysiology has not been extensively studied. Research suggests, however, that both direct stimulatory effects on the larynx and secondary effects of mucus production and mucus trafficking can create a range of laryngeal symptoms, including cough.
This review discusses the interaction of the upper and lower airway in respiratory disease, and focuses on the effect of these respiratory processes on laryngeal inflammation, function, and symptoms.
Chest 136 (5), 1406-7 (Nov 2009)
Fahim A, Morice AH;
Chronic cough is a common symptom with significant morbidity. We report a case of a 51-year-old woman who presented with chronic cough. She recently had received a diagnosis of glaucoma and had started receiving therapy with topical latanoprost. The onset of cough coincided with the use of latanoprost. We performed a citric acid cough challenge while the patient was receiving latanoprost and repeated the challenge after therapy with the drug was stopped. The initial cough challenge revealed marked hypersensitivity of the cough reflex. After stopping therapy with latanoprost for 10 days, the cough sensitivity was reduced significantly. Within 3 days of recommending therapy with latanoprost, the cough sensitivity increased to the initial value. This case illustrates that the topical application of latanoprost can markedly increase cough sensitivity, which is reversible on stopping administration of the drug. Moreover, the case reflects the clinical manifestation of the effect of topical latanoprost therapy on cough reflex, which, to our knowledge, has never been reported in the medical literature.