Acute bronchitis
302755
222503280
2008-06-29T18:09:07Z
98.207.168.223
The Merk Manual citation does not support the statements about "bacteria persisting," or that antihistamines & expectorants may be "doubly harmful." Citation or correction needed.
{{DiseaseDisorder infobox |
Name = Bronchitis |
ICD10 = {{ICD10|J|20||j|20}}-{{ICD10|J|21||j|20}} |
ICD9 = {{ICD9|466}} |
MeshID = D001991 |
}}
'''Bronchitis''' is an [[inflammation]] of the large [[bronchus|bronchi]] (medium-size airways) in the [[lung]]s. It can lead to [[pneumonia]]. ''Acute bronchitis'' is usually caused by [[virus]]es or [[bacteria]] and may last several days or weeks.<ref name="pmid17108344">{{cite journal |author=Wenzel RP, Fowler AA |title=Clinical practice. Acute bronchitis |journal=N. Engl. J. Med. |volume=355 |issue=20 |pages=2125–30 |year=2006 |pmid=17108344 |doi=10.1056/NEJMcp061493}}</ref> '''Acute bronchitis''' is characterized by [[cough]] and [[sputum]] (phlegm) production and symptoms related to the obstruction of the airways by the inflamed airways and the phlegm, such as shortness of breath and wheezing. Diagnosis is by clinical examination and sometimes [[microbiology|microbiological]] examination of the phlegm. Treatment may be with [[antibiotic]]s (if a bacterial infection is suspected), [[bronchodilator]]s (to relieve breathlessness) and other treatments.
==Cause/Etiology==
Acute bronchitis can be contagious. In about half of instances of acute bronchitis a bacterial or viral pathogen is identified.<ref name="pmid11209098">{{cite journal |author=Macfarlane J, Holmes W, Gard P, ''et al'' |title=Prospective study of the incidence, aetiology and outcome of adult lower respiratory tract illness in the community |journal=Thorax |volume=56 |issue=2 |pages=109–14 |year=2001 |pmid=11209098|doi=10.1136/thorax.56.2.109}}</ref> Typical viruses include [[Human respiratory syncytial virus|respiratory syncytial virus]], [[rhinovirus]], [[influenza]], and others.<ref name="pmid15260036">{{cite journal |author=Freymuth F, Vabret A, Gouarin S, ''et al'' |title=[Epidemiology and diagnosis of respiratory syncitial virus in adults] |language=French |journal=Revue des maladies respiratoires |volume=21 |issue=1 |pages=35–42 |year=2004 |pmid=15260036|doi=10.1016/S0761-8425(04)71233-4}}</ref>
Acute bronchitis can result from breathing irritating fumes, such as those of tobacco smoke or polluted air.<ref> [http://www.emedicinehealth.com/bronchitis/page2_em.htm#Bronchitis%20Causes Bronchitis]''emedicinehealth.com''. Retrieved on [[January 4]] [[2008]].</ref>
==Signs and symptoms==
Bronchitis may be indicated by an [[expectorate|expectorating]] [[cough]], shortness of breath ([[dyspnea]]) and wheezing. Occasionally [[chest pain]]s, [[fever]], and [[Fatigue (physical)|fatigue]] or [[malaise]] may also occur. Additionally, Bronchitis caused by [[Adenoviridae]] may cause systemic and gastrointestinal symptoms as well.<ref>{{cite web |url=http://www.cdc.gov/mmwR/preview/mmwrhtml/00053922.htm |title=Civilian Outbreak of Adenovirus Acute Respiratory Disease -- South Dakota, 1997 |accessdate=2007-10-08 |format= |work=}}</ref> However the coughs due to bronchitis can continue for up to three weeks or more even after all other symptoms have subsided.
==Diagnosis==
A [[physical examination]] will often reveal decreased intensity of breath sounds, wheezing, [[rhonchi]] and prolonged [[Exhalation|expiration]]. Most doctors rely on the presence of a persistent dry or wet cough as evidence of bronchitis.
A variety of tests may be performed in patients presenting with cough and shortness of breath:
* A [[chest X-ray]] that reveals hyperinflation; collapse and consolidation of lung areas would support a diagnosis of [[pneumonia]]. Some conditions that predispose to bronchitis may be indicated by chest radiography.
* A sputum sample showing [[neutrophil granulocyte]]s (inflammatory white blood cells) and [[microbiological culture|culture]] showing that has pathogenic microorganisms such as [[Streptococcus|Streptococcus spp.]]
* A [[blood test]] would indicate inflammation (as indicated by a raised [[white blood cell]] count and elevated [[C-reactive protein]]).
*Neutrophils infiltrate the lung tissue, aided by damage to the airways caused by irritation.
*Damage caused by irritation of the airways leads to inflammation and leads to neutrophils being present.
*Mucosal hypersecretion is promoted by a substance released by neutrophils.
*Further obstruction to the airways is caused by more goblet cells in the small airways. This is typical of chronic bronchitis.
*Although infection is not the reason or cause of chronic bronchitis it is seen to aid in sustaining the bronchitis.
== Treatment ==
===Antibiotics===
In most cases, acute bronchitis is caused by [[virus]]es, not [[bacteria]], and will go away on its own without antibiotics. To treat acute bronchitis that appears to be caused by a bacterial infection, or as a precaution, [[antibiotic]]s may be given.<ref>[http://www.merck.com/mmhe/sec04/ch041/ch041a.html The Merck Manual of Medical Information: Bronchitis]. February 2003. Accessed [[20 March]] [[2007]].</ref> Also, a [[meta-analysis]] found that antibiotics may reduce symptoms by one-half day.<ref name="pmid10403354">{{cite journal |author=Bent S, Saint S, Vittinghoff E, Grady D |title=Antibiotics in acute bronchitis: a meta-analysis |journal=Am. J. Med. |volume=107 |issue=1 |pages=62–7 |year=1999 |pmid=10403354 |doi=10.1016/S0002-9343(99)00167-9}}</ref>
===Smoking cessation===
{{details|Smoking cessation}}
To help the bronchial tree heal faster and not make bronchitis worse, [[tobacco smoking|smokers]] should cut back on the number of cigarettes smoked daily or quit smoking completely to allow their lungs to recover from the layer of tar that often builds up over time.<ref>[http://familydoctor.org/677.xml The American Academy of Family Physicians: Acute Bronchitis]. January 2006. Accessed [[20 March]] [[2007]].</ref>
===Antihistamines===
Using over-the-counter [[antihistamine]]s may be harmful in the self-treatment of bronchitis.<ref>[http://www.merck.com/mmhe/sec04/ch039/ch039b.html Merck Manual Home Edition: Symptoms and Diagnosis of Lung Disorders: Symptoms]. November 2006. Accessed [[6 October]] [[2007]].</ref>
An effect of antihistamines is to thicken mucus secretions. Expelling infected mucus via coughing can be beneficial in recovering from bronchitis. Expulsion of the mucus may be hindered if it is thickened. Antihistamines can help bacteria to persist{{Fact|date=June 2008}} and multiply in the lungs by increasing its [[residence time]] in a warm, moist environment of thickened mucus.
Using antihistamines along with an [[expectorant]] cough syrup may be doubly harmful{{Fact|date=June 2008}}: encouraging the production of mucus and then thickening that which is produced. Using an expectorant cough syrup alone might be useful in flushing bacteria from the lungs. Using an antihistamine along with it works against the intention of using the expectorant.
==Prognosis==
Acute bronchitis usually lasts a few days. <ref>
{{citation | title = Bronchitis | publisher = Mayo Foundation for Medical Education and Research | date = 2007-04-20 | url = http://www.mayoclinic.com/health/bronchitis/DS00031/DSECTION=1 | accessdate = 2008-05-30}}</ref> It may accompany or closely follow a cold or the flu, or may occur on its own. Bronchitis usually begins with a dry cough, including waking the sufferer at night. After a few days it progresses to a wetter or productive cough, which may be accompanied by fever, fatigue, and headache. The fever, fatigue, and malaise may last only a few days; but the wet cough may last up to several weeks.
Should the cough last longer than a month, some doctors may issue a referral to an [[Otorhinolaryngology|otorhinolaryngologist]] (ear, nose and throat doctor) to see if a condition other than bronchitis is causing the irritation. It is possible that having irritated bronchial tubes for as long as a few months may inspire asthmatic conditions in some patients.
In addition, if one starts coughing mucus tinged with blood, one should see a doctor. In rare cases, doctors may conduct tests to see if the cause is a serious condition such as [[tuberculosis]] or [[lung cancer]].
Acute bronchitis may lead to [[asthma]] or [[pneumonia]].{{Fact|date=October 2007}}
==Prevention==
In 1985, [[University of Newcastle, Australia]] Professor Robert Clancy developed an oral vaccine for acute bronchitis. This vaccine was commercialised four years later as [[Broncostat]].<ref>[http://www.biotechnology-innovation.com.au/innovations/pharmaceuticals/broncostat.html Broncostat]. ''Biotechnology.com''. Retrieved on [[October 3]] [[2007]].</ref>
== References ==
{{reflist}}
==See also==
* [[Chronic bronchitis]]
== External links ==
{{Wikisource1911Enc|Bronchitis}}
Online medical references:
*[http://www.lungsonline.com/bronchitis.html Bronchitis ] Lungs OnLine
*[http://familydoctor.org/677.xml Acute Bronchitis] FamilyDoctor.org (American Academy of Family Physicians)
{{Respiratory pathology}}
{{Common Cold}}
[[Category:Inflammations]]
[[Category:Pulmonology]]
[[Category:General practice]]
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