Asthma and gastroesophageal reflux
|
Asthma Microchapters |
|
Diagnosis |
|---|
|
Other Diagnostic Studies |
|
Treatment |
|
Case Studies |
|
Asthma and gastroesophageal reflux On the Web |
|
American Roentgen Ray Society Images of Asthma and gastroesophageal reflux |
|
Risk calculators and risk factors for Asthma and gastroesophageal reflux |
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-In-Chief: Varun Kumar, M.B.B.S. [2]
Overview
The underlying gastro-esophageal reflux disease predisposes the patient to have repetitive episodes of acid aspiration, which subsequently causes repeated airway inflammation and results in irritant-induced asthma.[1][2] The incidence of GERD in patients with asthma is approximately 38%. Asthmatics resistant to therapy are commonly associated with GERD, but identification and treatment of GERD has not shown to relate to the improvement in asthmatic control.[3]
Pathophysiology
There are four mechanisms proposed to explain the pathophysiology of development of asthma in patients with GERD:
- Vagal reflex: Both the esophagus and the bronchial tree are innervated by vagus nerve as they both share a common embryonic origin. Therefore when there is reflux of acid contents from the stomach into the esophagus, the receptors in esophagus are stimulated causing firing of vagus nerve which results in bronchospasm. This phenomenon was demonstrated by Mansfield and Stein by intraesophageal acid provocation test resulting in increased resistance to airflow[4] and further strengthened by another series involving 136 subjects[5]. However, many studies failed to demonstrate a significant relationship between acid reflux and pulmonary function[6][7].
- Heightened Bronchial Reactivity: Acid reflux into esophagus, increases the bronchial response to other stimuli. This was demonstrated by increased bronchial response to methacholine challenge test[8].
References
- ↑ Cuevas Hernández MM, Arias Hernández RM (2008) [Pulmonary gammagraphy study in asthmatic children with gastroesophageal reflux.] Rev Alerg Mex 55 (6):229-33. PMID: 19157219
- ↑ Shapiro GG, Christie DL (1983) Gastroesophageal reflux and asthma. Clin Rev Allergy 1 (1):39-56. PMID: 6142759
- ↑ Leggett JJ, Johnston BT, Mills M, Gamble J, Heaney LG (2005) Prevalence of gastroesophageal reflux in difficult asthma: relationship to asthma outcome. Chest 127 (4):1227-31. DOI:10.1378/chest.127.4.1227 PMID: 15821199
- ↑ Mansfield LE, Stein MR (1978). "Gastroesophageal reflux and asthma: a possible reflex mechanism". Ann Allergy. 41 (4): 224–6. PMID 707849.
- ↑ Wright RA, Miller SA, Corsello BF (1990). "Acid-induced esophagobronchial-cardiac reflexes in humans". Gastroenterology. 99 (1): 71–3. PMID 2344943.
- ↑ Field SK (1999). "A critical review of the studies of the effects of simulated or real gastroesophageal reflux on pulmonary function in asthmatic adults". Chest. 115 (3): 848–56. PMID 10084501.
- ↑ Tan WC, Martin RJ, Pandey R, Ballard RD (1990). "Effects of spontaneous and simulated gastroesophageal reflux on sleeping asthmatics". Am Rev Respir Dis. 141 (6): 1394–9. PMID 2350084.
- ↑ Herve P, Denjean A, Jian R, Simonneau G, Duroux P (1986). "Intraesophageal perfusion of acid increases the bronchomotor response to methacholine and to isocapnic hyperventilation in asthmatic subjects". Am Rev Respir Dis. 134 (5): 986–9. PMID 3096180.