Bronchiolitis
| Bronchiolitis | |
|---|---|
| Classification and external resources | |
 An x ray of a child with RSV showing the typical bilateral perihilar fullness of bronchiolitis. |
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| ICD-10 | J21 |
| ICD-9 | 466.1 |
| DiseasesDB | 1701 |
| MedlinePlus | 000975 |
| eMedicine | emerg/365 |
| MeSH | D001988 |
Bronchiolitis is inflammation of the bronchioles, the smallest air passages of the lungs. It usually occurs in children less than two years of age and presents with coughing, wheezing, and shortness of breath. This inflammation is usually caused by respiratory syncytial virus.[1] Treatment is typically supportive[2] but may involve the use of nebulized epinephrine or hypertonic saline.
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[edit] Signs and symptoms
In a typical case, an infant under two years of age develops cough, wheeze, and shortness of breath over one or two days. The infant may be breathless for several days. After the acute illness, it is common for the airways to remain sensitive for several weeks, leading to recurrent cough and wheeze.
[edit] Causes
The term usually refers to acute viral bronchiolitis, a common disease in infancy. This is most commonly caused by respiratory syncytial virus (RSV, also known as human pneumovirus). Other viruses which may cause this illness include metapneumovirus, influenza, parainfluenza, coronavirus, adenovirus, and rhinovirus.
Studies have shown there is a link between voluntary caesarean birth and an increased prevalence of bronchiolitis. A recent study by Perth's Telethon Institute for Child Health Research has shown an 11% increase in hospital admissions for children delivered this way.[3]
[edit] Diagnosis
The diagnosis is typically made by clinical examination. Chest X-ray is sometimes useful to exclude pneumonia, but not indicated in routine cases.[4]
Testing for the specific viral cause can be done but has little effect on management and thus is not routinely recommended.[4] RSV testing by direct immunofluorescence testing on nasopharyngeal aspirate had a sensitivity of 61% and specificity of 89%.[5] Identification of those who are RSV-positive can help for: disease surveillance, grouping ("cohorting") people together in hospital wards to prevent cross infection, predicting whether the disease course has peaked yet, reducing the need for other diagnostic procedures (by providing confidence that a cause has been identified).
Infants with bronchiolitis between the age of two and three months have a second infection by bacteria (usually a urinary tract infection) less than 6% of the time.[6]
[edit] Prevention
In general, prevention of bronchiolitis relies on measures to reduce the spread of the viruses that cause respiratory infections (that is, handwashing, and avoiding exposure to those symptomatic with respiratory infections).
Premature infants, and others with certain major cardiac and respiratory disorders, can receive passive immunization with Palivizumab (a monoclonal antibody against RSV). This form of passive immunization therapy requires monthly injections every winter. Whether it could benefit infants with lung problems secondary to muscular dystrophies and other vulnerable groups is currently unknown
[edit] Management
[edit] Inhaled epinephrine
Nebulized and inhaled epinephrine (both racemic and levo(1)-epinephrine) has been shown to decrease hospitalization rates.[7][8]
[edit] Nebulized hypertonic saline
Nebulized and inhaled hypertonic saline (3%) appears to be effective in improving clinical outcomes and shortening the duration of hospital stay.[4]
[edit] Other medications
Currently other medications do not yet have evidence to support their use.[8]
[edit] Non-effective treatments
Ribavirin is an antiviral drug which does not appear to be effective for bronchiolitis.[9] Antibiotics are often given in case of a bacterial infection complicating bronchiolitis, but have no effect on the underlying viral infection.[9] Corticosteroids have no proven benefit in bronchiolitis treatment and are not advised.[9] DNAse has not been found to be effective.[10]
[edit] Epidemiology
90% of the patients are aged between 1 and 9 months old. Bronchiolitis is the most common cause of hospitalization up to the first year of life. It is epidemic in winters.
[edit] References
- ^ Smyth RL, Openshaw PJ (July 2006). "Bronchiolitis". Lancet 368 (9532): 312–22. doi:10.1016/S0140-6736(06)69077-6. PMID 16860701. http://linkinghub.elsevier.com/retrieve/pii/S0140-6736(06)69077-6.
- ^ Wright, M; Mullett CJ, Piedimonte G et al. (October 2008). "Pharmacological management of acute bronchiolitis". Veterinary Research 4 (5): 895–903. PMC 2621418. PMID 19209271. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2621418.
- ^ http://www.abc.net.au/news/2011-10-31/elective-caesarean-heightens-respiratory-risk/3611358
- ^ a b c Zorc, JJ; Hall, CB (2010 Feb). "Bronchiolitis: recent evidence on diagnosis and management". Pediatrics 125 (2): 342–9. doi:10.1542/peds.2009-2092. PMID 20100768.
- ^ Bordley WC, Viswanathan M, King VJ, Sutton SF, Jackman AM, Sterling L et al. (2004). "Diagnosis and testing in bronchiolitis: a systematic review". Arch Pediatr Adolesc Med 158 (2): 119–26. doi:10.1001/archpedi.158.2.119. PMID 14757603.
- ^ Ralston, S; Hill, V, Waters, A (2011 Oct). "Occult serious bacterial infection in infants younger than 60 to 90 days with bronchiolitis: a systematic review.". Archives of pediatrics & adolescent medicine 165 (10): 951–6. PMID 21969396.
- ^ Hartling L, Bialy LM, Vandermeer B, Tjosvold L, Johnson DW, Plint AC et al. (2011). "Epinephrine for bronchiolitis.". Cochrane Database Syst Rev (6): CD003123. doi:10.1002/14651858.CD003123.pub3. PMID 21678340.
- ^ a b Hartling, L; Fernandes, RM, Bialy, L, Milne, A, Johnson, D, Plint, A, Klassen, TP, Vandermeer, B (2011 Apr 6). "Steroids and bronchodilators for acute bronchiolitis in the first two years of life: systematic review and meta-analysis". BMJ (Clinical research ed.) 342: d1714. doi:10.1136/bmj.d1714. PMC 3071611. PMID 21471175. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3071611.
- ^ a b c Bourke, T; Shields, M (2011 Apr 11). "Bronchiolitis". Clinical evidence 2011. PMID 21486501.
- ^ "BestBets: Do recombinant DNAse improve clinical outcome in an infant with RSV positive bronchiolitis?". http://www.bestbets.org/bets/bet.php?id=847.
[edit] External links
- Bronchiolitis. Patient information from NHS Direct
- Bronchiolitis in children - A national clinical guidelinePDF (1.74 MB) from the Scottish Intercollegiate Guidelines Network
- Diagnosis and Management of Bronchiolitis from the AAP
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Look up bronchiolitis in Wiktionary, the free dictionary. |
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