Dr. Sheldon Mintz on Chronic Cough as seen by a respirologist.
Chronic cough is cough lasting more than 8 weeks in adults, a common complaint in about 10% of population. Chronic cough is (somewhat arbitrarily) defined as coughing that goes on for at least 8 weeks. One measurement tool is the LCQ: the Leicester Cough Questionnaire.
Objective evaluation of cough is a challenge - ask, visual analogue scale, questionnaires, cough frequency monitors, capsaicin provocation test.
Chronic cough is a big deal for subjects suffering from it and should be treated with respect.
Common causes of cough: Asthma, GERD, upper airway syndrome, ACEI, occupational exposures. Dr. Mintz: suggests upper airway syndrome as a new term for post nasal drip. Is “upper airway cough syndrome” allergic cough? Upper airway cough syndrome AKA post nasal drip syndrome. Sinus CTs not helpful. Many positives and negatives.
Cough variant asthma is just plain asthma with cough replacing wheeze as a symptom. Cough variant is asthma plain and simple, you mainly cough instead wheeze (ie objective testing is also positive for asthma). Cough variant asthma: +PFT/bronchodilator or methacholine challenge, same as asthma where cough replaces wheeze. Treat as usual.
GERD associated cough: Clinical pearl: cough occurring immediately on recumbency often responds to PPI. Classic symptoms of GERD may be absent. Empiric approach: PPI for 2-8 weeks and investigate further if no response. The question: ‘does your cough start as soon as you lie down’ suggests the diagnosis of GERD-induced cough. The reflux itself is often ‘silent’ (ie there’s no burning sensation) but PPI treatment can help dramatically. GERD associated cough - classic symptoms of GERD may be absent. Can take up to 8 weeks to respond to PPIs. Esophageal Impedance monitor can be used for diagnosis. Controversy on GERD cough: recommended lifestyle modifications, not PPI. Strong placebo effect has been noted in some studies.
Chronic cough - there are the common causes GERD, Rhinitis, and Asthma but don’t forget Infectious causes, e.g. Pertussis or the 100 Day cough - Macrolides for treatment but the cough still lasts. Chronic cough, think pertussis! 50% of cases now in adults as vaccine immunity wanes (or unimmunized kids). Catarrhal stage = URI. Paroxysmal stage = Severe cough. Followed by chronic cough.
OSA and Cough: chronic cough in 33% of adults with OSA. Upper airway inflammation or associated GERD. No associated daytime somnolence, but snoring and heartburn. Chronic cough in 33% of obstructive sleep apnea patients; gets better with nasal CPAP.
Dr. Mariam Hanna, MD @PedsAllergyDoc
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