Bronchiolitis occurs mainly in [[infants]]. The patient usually gives a history of [[nasal congestion]] and expectoration of [[phlegm]]. The classical presentation of bronchiolitis is [[fever]], [[cough]], and [[dyspnea]]. The [[virus]] is transmitted from person to person by direct contact with [[nasal]] [[fluids]] or via [[Airborne transmission|airborne droplets]]. Although [[Human respiratory syncytial virus|RSV]] generally causes only mild [[symptoms]] in [[Adult|adults]], it can cause severe [[illness]] in an [[infant]]. [[Bronchiolitis]] is seasonal and appears more often in the fall and winter months. Bronchiolitis is a very common reason for infants to be hospitalized during winter and early spring. It has been estimated that by 1 year of age, more than half of all [[infants]] have been exposed to [[RSV]].
Common symptoms of bronchiolitis include [[fever]], [[cough]], [[dyspnea]], and [[Nasal discharge]]. Other symptoms include post tussive [[vomiting]] and [[dehydration]].
==History and Symptoms==
==History and Symptoms==
*Bronchiolitis should be suspected when acute onset of [[upper respiratory tract infection]] appears, followed by [[lower respiratory tract infection]] [[symptoms]] ([[wheezing]], [[cough]], and [[shortness of breath]]), in a child younger than 2 years.<ref name="Mandell">{{Cite book | last1 = Mandell | first1 = Gerald L. | last2 = Bennett | first2 = John E. (John Eugene) | last3 = Dolin | first3 = Raphael. | title = Mandell, Douglas, and Bennett's principles and practice of infectious disease | date = 2010 | publisher = Churchill Livingstone/Elsevier | location = Philadelphia, PA | isbn = | pages = }}</ref><ref name="pmid27549684">{{cite journal| author=Florin TA, Plint AC, Zorc JJ| title=Viral bronchiolitis. | journal=Lancet | year= 2017 | volume= 389 | issue= 10065 | pages= 211-224 | pmid=27549684 | doi=10.1016/S0140-6736(16)30951-5 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27549684 }} </ref>
*The [[incubation period]] of [[Human respiratory syncytial virus|respiratory syncytial virus (RSV)]] is 2-8 days; therefore [[symptoms]] begin within one week of contact with a [[symptomatic]] patient.<ref name="pmid19209271">{{cite journal| author=Wright M, Mullett CJ, Piedimonte G| title=Pharmacological management of acute bronchiolitis. | journal=Ther Clin Risk Manag | year= 2008 | volume= 4 | issue= 5 | pages= 895-903 | pmid=19209271 | doi= | pmc=PMC2621418 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19209271 }} </ref>
=== Common symptoms ===
*Patients usually present with [[symptoms]] of a mild [[upper respiratory infection]] which include [[fever]], [[cough]], and [[nasal discharge]].<ref name="pmid19209271">{{cite journal| author=Wright M, Mullett CJ, Piedimonte G| title=Pharmacological management of acute bronchiolitis. | journal=Ther Clin Risk Manag | year= 2008 | volume= 4 | issue= 5 | pages= 895-903 | pmid=19209271 | doi= | pmc=PMC2621418 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19209271 }} </ref>
Common symptoms of bronchiolitis include the following: <ref name="Mandell">{{Cite book | last1 = Mandell | first1 = Gerald L. | last2 = Bennett | first2 = John E. (John Eugene) | last3 = Dolin | first3 = Raphael. | title = Mandell, Douglas, and Bennett's principles and practice of infectious disease | date = 2010 | publisher = Churchill Livingstone/Elsevier | location = Philadelphia, PA | isbn = | pages = }}</ref><ref name="pmid27549684">{{cite journal| author=Florin TA, Plint AC, Zorc JJ| title=Viral bronchiolitis. | journal=Lancet | year= 2017 | volume= 389 | issue= 10065 | pages= 211-224 | pmid=27549684 | doi=10.1016/S0140-6736(16)30951-5 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=27549684 }} </ref><ref name="pmid19209271">{{cite journal| author=Wright M, Mullett CJ, Piedimonte G| title=Pharmacological management of acute bronchiolitis. | journal=Ther Clin Risk Manag | year= 2008 | volume= 4 | issue= 5 | pages= 895-903 | pmid=19209271 | doi= | pmc=PMC2621418 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19209271 }} </ref>
*[[Symptoms]] of [[lower respiratory tract infection]] include:<ref name="Mandell">{{Cite book | last1 = Mandell | first1 = Gerald L. | last2 = Bennett | first2 = John E. (John Eugene) | last3 = Dolin | first3 = Raphael. | title = Mandell, Douglas, and Bennett's principles and practice of infectious disease | date = 2010 | publisher = Churchill Livingstone/Elsevier | location = Philadelphia, PA | isbn = | pages = }}</ref>
* [[cough]]
:*Dry [[cough]]
*[[Wheezing]]
:*[[Wheezing]]
*[[Shortness of breath]]
:*[[Shortness of breath]]
*[[Fever]]
:*[[Fever]]
*[[Tachypnea]]
:*[[Tachypnea]]
*[[Fever]] is usually not high; in the case of high [[fever]], other causes should be ruled out, such as [[bacterial infections]].
*[[Lethargy]]
*[[Apnea]] is a severe manifestation of [[RSV]] [[infection]] and is more common in children under 3 months of age and [[premature]] infants.<ref name="pmid19209271">{{cite journal| author=Wright M, Mullett CJ, Piedimonte G| title=Pharmacological management of acute bronchiolitis. | journal=Ther Clin Risk Manag | year= 2008 | volume= 4 | issue= 5 | pages= 895-903 | pmid=19209271 | doi= | pmc=PMC2621418 | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=19209271 }} </ref>
*[[Nasal discharge]]
*[[Lethargy]] is also common, as [[vomit]] can be secondary to [[cough]] and poor feeding secondary to [[tachypnea]] may lead to [[dehydration]].<ref name="Mandell">{{Cite book | last1 = Mandell | first1 = Gerald L. | last2 = Bennett | first2 = John E. (John Eugene) | last3 = Dolin | first3 = Raphael. | title = Mandell, Douglas, and Bennett's principles and practice of infectious disease | date = 2010 | publisher = Churchill Livingstone/Elsevier | location = Philadelphia, PA | isbn = | pages = }}</ref>
*History of [[cyanosis]] is related to severe disease.<ref name="pmid16860701">{{cite journal| author=Smyth RL, Openshaw PJ| title=Bronchiolitis. | journal=Lancet | year= 2006 | volume= 368 | issue= 9532 | pages= 312-22 | pmid=16860701 | doi=10.1016/S0140-6736(06)69077-6 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16860701 }} </ref>
=== Less common sympotms ===
Less common symptoms of bronchiolitis include the following:<ref name="Mandell">{{Cite book | last1 = Mandell | first1 = Gerald L. | last2 = Bennett | first2 = John E. (John Eugene) | last3 = Dolin | first3 = Raphael. | title = Mandell, Douglas, and Bennett's principles and practice of infectious disease | date = 2010 | publisher = Churchill Livingstone/Elsevier | location = Philadelphia, PA | isbn = | pages = }}</ref><ref name="pmid16860701">{{cite journal| author=Smyth RL, Openshaw PJ| title=Bronchiolitis. | journal=Lancet | year= 2006 | volume= 368 | issue= 9532 | pages= 312-22 | pmid=16860701 | doi=10.1016/S0140-6736(06)69077-6 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16860701 }} </ref>
↑ 1.01.1Mandell, Gerald L.; Bennett, John E. (John Eugene); Dolin, Raphael. (2010). Mandell, Douglas, and Bennett's principles and practice of infectious disease. Philadelphia, PA: Churchill Livingstone/Elsevier.