SELECTED ARTICLES FROM THE RECENT LITERATURE 2004
12/29/04
Chronic cough evaluation
Summary
Background - Chronic cough (CC) is one of the most common chronic complaints seen in primary care community practice.
Findings - The causes of CC in non-smokers and in the face of a normal chest x-ray were reviewed by Alva and Dicpinigaitis of the Montefiore Medical Center in New York. They pointed out that the most common causes of CC in such individuals are: 1) post nasal drip syndrome (PNDS); 2) cough variant asthma; or 3) gastro-esophageal reflux (GER). Therefore, empiric treatment of such conditions may be the most simple, cost effective approach to CC in these patients. In particular, they recommended treatment of the PNDS with a combination of a first generation antihistamine and a decongestant, rather than use of the more recent non-sedating antihistamines because of the anti-cholinergic effects of the older antihistamines that might cause drying of the PND.
Reference
J Respir Dis 2004;25:419-425
Editor's Comments
These comments about the causes of CC are similar to that frequently expressed by Irwin and colleagues in the Univ. of Massachusetts, long-time investigators of CC. Another cause of CC in adults identified increasingly in recent years has been pertussis (Pert) infection, even in individuals who previously received the pertussis vaccine. Some reports describe evidence suggesting that Pert infection may be responsible for 10-15% of prolonged, persistent cough in previously healthy adults (see J Infect Dis 2002;186:415-18). Such Pert infections may occur in immunized individuals because the older cellular pertussis vaccine has been only about 70% effective in inducing protective immunity. Also, such immunity may wane after a period of about 10-15 years. Because a number of adults never previously received the Pert vaccine as children, there have always been significant foci of Pert infection in the USA which may be manifested in adults as CC without the characteristic whoop sound.
Although these authors recommend a trial of antihistamine-decongestant combinations as empiric therapy for the PNDS, in my experience treatment with intranasal steroid sprays (e.g., Nasacort, Nasonex) has been more successful in this regard. However, it may take several weeks of such nasal steroid treatment before improvement in the CC occurs.
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