Bronchiolitis occurs mainly in the infants. The patients usually give history of [[nasal congestion]] and [[phlegm]] [[discharge]]. Its classical presentation is [[fever]], [[cough]] and [[dyspnea]]. The [[virus]] is transmitted from person to person by direct contact with nasal fluids, or by airborne droplets. Although [[Human respiratory syncytial virus|Respiratory syncytial virus (RSV)]] generally causes only mild symptoms in an adult, it can cause severe illness in an infant. Bronchiolitis is seasonal and appears more often in the fall and winter months. It is a very common reason for infants to be hospitalized during winter and early spring. It is estimated that by their first year, more than half of all infants have been exposed to [[Respiratory syncytial virus|Respiratory syncytial virus (RSV)]].<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>
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 the virus is of 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 start with symptoms of a mild upper respiratory infection which includes [[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 case of high [[fever]] other causes should ruled out, such as bacterial infections.
*[[Lethargy]]
*[[Apnea]] is a severe manifestation of [[RSV]] infection, 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 with 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.