The concept of a 'united airway' became popular to link allergic rhinitis and asthma in many individuals who had symptoms of both upper and lower airway disease. Because of the common epithelium that runs all the way down the airway it is not surprising that in many individuals allergens trigger inflammation in both sites. However, the mere fact that some individuals have both symptoms of rhinitis and lower airway pathology does not mean the condition has an atopic basis.
Since the airway has a limited number of ways of expressing symptoms, namely runny, sneezy, itchy and blocked nose, as well as cough or wheeze, these symptoms may also be produced in individuals who have quite a long list of other disease states. Although these are less common, healthcare workers will have to consider at some time that symptoms may be from primary ciliary dyskinesia, immune deficiency (primary or secondary), cystic fibrosis, Samter's triad or even recurrent viral airway infections.
This article explores these conditions, suggesting their pathophysiology and symptom base. A clear message, to think of one of these conditions if symptoms do not have an allergy base and do not respond to first-line therapy, is expressed.