Classification and external resources

The steeple sign as seen on an AP neck X-ray of a child with croup
ICD-10 J05.0
ICD-9 464.4
DiseasesDB 13233
MedlinePlus 000959
eMedicine ped/510 emerg/370 radio/199
MeSH D003440

Croup (or laryngotracheobronchitis) is a respiratory condition that is usually triggered by an acute viral infection of the upper airway. The infection leads to swelling inside the throat, which interferes with normal breathing and produces the classical symptoms of a "barking" cough, stridor, and hoarseness. It may produce mild, moderate, or severe symptoms, which often worsen at night. It is often treated with a single dose of oral steroids; occasionally epinephrine is used in more severe cases. Hospitalization is rarely required.

Croup is diagnosed on clinical grounds, once potentially more severe causes of symptoms have been excluded (i.e. epiglottitis or an airway foreign body). Further investigations—such as blood tests, X-rays, and cultures—are usually not needed. It is a relatively common condition that affects about 15% of children at some point, most commonly between 6 months and 5–6 years of age. It is almost never seen in teenagers or adults.

Once due primarily to diphtheria, this cause is now primarily of historical significance in the Western world due to the success of vaccination, and improved hygiene and living standards.


Signs and symptoms

Croup is characterized by a "barking" cough, stridor, hoarseness, and difficult breathing which usually worsens at night.[1] The "barking" cough is often described as resembling the call of a seal or sea lion.[2] The stridor is worsened by agitation or crying, and if it can be heard at rest, it may indicate critical narrowing of the airways. As croup worsens, stridor may decrease considerably.[1]

Other symptoms include fever, coryza (symptoms typical of the common cold), and chest wall indrawing.[1][3] Drooling or a very sick appearance indicate other medical conditions.[3]


Croup is usually deemed to be due to a viral infection.[1][4] Others use the term more broadly, to include acute laryngotracheitis, spasmodic croup, laryngeal diphtheria, bacterial tracheitis, laryngotracheobronchitis, and laryngotracheobronchopneumonitis. The first two conditions involve a viral infection and are generally milder with respect to symptomatology; the last four are due to bacterial infection and are usually of greater severity.[2]


Viral croup/acute laryngotracheitis is caused by parainfluenza virus, primarily types 1 and 2, in 75% of cases.[5] Other viral etiologies include influenza A and B, measles, adenovirus and respiratory syncytial virus (RSV).[2] Spasmodic croup is caused by the same group of viruses as acute laryngotracheitis, but lacks the usual signs of infection (such as fever, sore throat, and increased white blood cell count).[2] Treatment, and response to treatment, are also similar.[5]


Bacterial croup may be divided into laryngeal diphtheria, bacterial tracheitis, laryngotracheobronchitis, and laryngotracheobronchopneumonitis.[2] Laryngeal diphtheria is due to Corynebacterium diphtheriae while bacterial tracheitis, laryngotracheobronchitis, and laryngotracheobronchopneumonitis are usually due to a primary viral infection with secondary bacterial growth. The most common bacteria implicated are Staphylococcus aureus, Streptococcus pneumoniae, Hemophilus influenzae, and Moraxella catarrhalis.[2]


The viral infection that causes croup leads to swelling of the larynx, trachea, and large bronchi[4] due to infiltration of white blood cells (especially histiocytes, lymphocytes, plasma cells, and neutrophils).[2] Swelling produces airway obstruction which, when significant, leads to dramatically increased work of breathing and the characteristic turbulent, noisy airflow known as stridor.[4]


The Westley Score: Classification of croup severity[5][6]
Feature Number of points assigned for this feature
0 1 2 3 4 5
Chest wall
None Mild Moderate Severe
Stridor None With
At rest
Cyanosis None With
At rest
Level of
Normal Disoriented
Air entry Normal Decreased Markedly decreased

Croup is a clinical diagnosis.[4] The first step is to exclude other obstructive conditions of the upper airway, especially epiglottitis, an airway foreign body, subglottic stenosis, angioedema, retropharyngeal abscess, and bacterial tracheitis.[2][4]

A frontal X-ray of the neck is not routinely performed,[4] but if it is done, it may show a characteristic narrowing of the trachea, called the steeple sign. The steeple sign is suggestive of the diagnosis, but is absent in half of cases.[3]

Other investigations (such as blood tests and viral culture) are discouraged, as they may cause unnecessary agitation and thus worsen the stress on the compromised airway.[4] While viral cultures, obtained via nasopharyngeal aspiration, can be used to confirm the exact cause, these are usually restricted to research settings.[1] Bacterial infection should be considered if a person does not improve with standard treatment, at which point further investigations may be indicated.[2]


The most commonly used system for classifying the severity of croup is the Westley score. It is primarily used for research purposes rather than in clinical practice.[2] It is the sum of points assigned for five factors: level of consciousness, cyanosis, stridor, air entry, and retractions.[2] The points given for each factor is listed in the table to the right, and the final score ranges from 0 to 17.[6]

  • A total score of ≤ 2 indicates mild croup. The characteristic barking cough and hoarseness may be present, but there is no stridor at rest.[5]
  • A total score of 3–5 is classified as moderate croup. It presents with easily heard stridor, but with few other signs.[5]
  • A total score of 6–11 is severe croup. It also presents with obvious stridor, but also features marked chest wall indrawing.[5]
  • A total score of ≥ 12 indicates impending respiratory failure. The barking cough and stridor may no longer be prominent at this stage.[5]

85% of children presenting to the emergency department have mild disease; severe croup is rare (<1%).[5]


Many cases of croup have been prevented by immunization for influenza and diphtheria. At one time, croup referred to a diphtherial disease, but with vaccination, diphtheria is now rare in the developed world.[2]


Children with croup are generally kept as calm as possible.[4] Steroids are given routinely, with epinephrine used in severe cases.[4] Children with oxygen saturations under 92% should receive oxygen,[2] and those with severe croup may be hospitalized for observation.[3] If oxygen is needed, "blow-by" administration (holding an oxygen source near the child's face) is recommended, as it causes less agitation than use of a mask.[2] With treatment, less than 0.2% of people require endotracheal intubation.[6]


Corticosteroids, such as dexamethasone and budesonide, have been shown to improve outcomes in children with all severities of croup.[7] Significant relief is obtained as early as six hours after administration.[7] While effective when given orally, parenterally, or by inhalation, the oral route is preferred.[4] A single dose is usually all that is required, and is generally considered to be quite safe.[4] Dexamethasone at doses of 0.15, 0.3 and 0.6 mg/kg appear to be all equally effective.[8]


Moderate to severe croup may be improved temporarily with nebulized epinephrine.[4] While epinephrine typically produces a reduction in croup severity within 10–30 minutes, the benefits last for only about 2 hours.[1][4] If the condition remains improved for 2–4 hours after treatment and no other complications arise, the child is typically discharged from the hospital.[1][4]


While other treatments for croup have been studied, none have sufficient evidence to support their use. Inhalation of hot steam or humidified air is a traditional self-care treatment, but clinical studies have failed to show effectiveness[2][4] and currently it is rarely used.[9] The use of cough medicines, which usually contain dextromethorphan and/or guiafenesin, are also discouraged.[1] While breathing heliox (a mixture of helium and oxygen) to decrease the work of breathing has been used in the past, there is very little evidence to support its use.[10] Since croup is usually a viral disease, antibiotics are not used unless secondary bacterial infection is suspected.[1] In cases of possible secondary bacterial infection, the antibiotics vancomycin and cefotaxime are recommended.[2] In severe cases associated with influenza A or B, the antiviral neuraminidase inhibitors may be administered.[2]


Viral croup is usually a self-limited disease, but can very rarely result in death from respiratory failure and/or cardiac arrest.[1] Symptoms usually improve within two days, but may last for up to seven days.[5] Other uncommon complications include bacterial tracheitis, pneumonia, and pulmonary edema.[5]


Croup affects about 15% of children, and usually presents between the ages of 6 months and 5–6 years.[2][4] It accounts for about 5% of hospital admissions in this population.[5] In rare cases, it may occur in children as young as 3 months and as old as 15 years.[5] Males are affected 50% more frequently than are females, and there is an increased prevalence in autumn (fall).[2]


The word croup comes from the Early Modern English verb croup, meaning "to cry hoarsely"; the name was first applied to the disease in Scotland and popularized in the 18th century.[11] Diphtheritic croup has been known since the time of Homer's Ancient Greece and it was not until 1826 that viral croup was differentiated from croup due to diphtheria by Bretonneau.[12] Viral croup was thus called "faux-croup" by the French, as "croup" then referred to a disease caused by the diphtheria bacteria.[9] Croup due to diphtheria has become nearly unknown due to the advent of effective immunization.[12]


  1. ^ a b c d e f g h i j Rajapaksa S, Starr M (May 2010). "Croup – assessment and management". Aust Fam Physician 39 (5): 280–2. PMID 20485713. 
  2. ^ a b c d e f g h i j k l m n o p q r s Cherry JD (2008). "Clinical practice. Croup". N. Engl. J. Med. 358 (4): 384–91. doi:10.1056/NEJMcp072022. PMID 18216359. 
  3. ^ a b c d "Diagnosis and Management of Croup" (PDF). BC Children’s Hospital Division of Pediatric Emergency Medicine Clinical Practice Guidelines. 
  4. ^ a b c d e f g h i j k l m n o p Everard ML (February 2009). "Acute bronchiolitis and croup". Pediatr. Clin. North Am. 56 (1): 119–33, x–xi. doi:10.1016/j.pcl.2008.10.007. PMID 19135584. 
  5. ^ a b c d e f g h i j k l Johnson D (2009). "Croup". Clin Evid (Online) 2009. PMC 2907784. PMID 19445760. 
  6. ^ a b c Klassen TP (December 1999). "Croup. A current perspective". Pediatr. Clin. North Am. 46 (6): 1167–78. doi:10.1016/S0031-3955(05)70180-2. PMID 10629679. 
  7. ^ a b Russell KF, Liang Y, O'Gorman K, Johnson DW, Klassen TP (2011). Klassen, Terry P. ed. "Glucocorticoids for croup". Cochrane Database Syst Rev 1 (1): CD001955. doi:10.1002/14651858.CD001955.pub3. PMID 21249651. 
  8. ^ Port C (April 2009). "Towards evidence based emergency medicine: best BETs from the Manchester Royal Infirmary. BET 4. Dose of dexamethasone in croup". Emerg Med J 26 (4): 291–2. doi:10.1136/emj.2009.072090. PMID 19307398. 
  9. ^ a b Marchessault V (November 2001). "Historical review of croup". Can J Infect Dis 12 (6): 337–9. PMC 2094841. PMID 18159359. 
  10. ^ Vorwerk C, Coats T (2010). Vorwerk, Christiane. ed. "Heliox for croup in children". Cochrane Database Syst Rev 2 (2): CD006822. doi:10.1002/14651858.CD006822.pub2. PMID 20166089. 
  11. ^ Online Etymological Dictionary, croup. Accessed 2010-09-13.
  12. ^ a b Feigin, Ralph D. (2004). Textbook of pediatric infectious diseases. Philadelphia: Saunders. p. 252. ISBN 0-7216-9329-6. 

External links

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(especially of a horse), , / (trachealis)

Look at other dictionaries:

  • croup — croup …   Dictionnaire des rimes

  • croup — [ krup ] n. m. • 1773; mot angl. dial., probablt d orig. onomat. ♦ Vieilli Laryngite pseudomembraneuse, de nature diphtérique. Cet enfant est mort du croup. Faux croup : spasme du larynx, bénin. ⊗ HOM. Croupe. ● croup nom masculin (anglais croup …   Encyclopédie Universelle

  • Croup — (kr[=oo]p), n. [Scot. croup, cf. croup, crowp, to croak, to cry or speak with a hoarse voice; cf. also LG. kropp, G. kropf, the crop or craw of a bird, and tumor on the anterior part of the neck, a wen, etc. Cf. {Crop}.] (Med.) An inflammatory… …   The Collaborative International Dictionary of English

  • croup|y — «KROO pee», adjective, croup|i|er, croup|i|est. 1. sick with croup. 2. hoarse and having difficulty in breathing: »the wheeze of a croupy baby …   Useful english dictionary

  • Croup — (kr[=oo]p), n. [F. croupe hind quarters, croup, rump, of German or Icel. origin; cf. Icel. kryppa hump; akin to Icel. kroppr. Cf. {Crop}.] The hinder part or buttocks of certain quadrupeds, especially of a horse; hence, the place behind the… …   The Collaborative International Dictionary of English

  • croup — Ⅰ. croup [1] ► NOUN ▪ inflammation of the larynx and trachea in children, causing breathing difficulties. ORIGIN from dialect croup «to croak». Ⅱ. croup [2] ► NOUN ▪ the rump or hindquarters of a horse …   English terms dictionary

  • croup — [kru:p] n [U] [Date: 1700 1800; Origin: croup to croak, cough (16 19 centuries), from the sound] an illness in children which makes them cough and have difficulty breathing …   Dictionary of contemporary English

  • croup — coughing illness, 1765, from obsolete verb croup to cry hoarsely, croak (1510s), probably echoic. This was the local name of the disease in southeastern Scotland, given wide currency by Dr. Francis Home (1719 1813) of Edinburgh in his 1765… …   Etymology dictionary

  • croup — croup; croup·ous; …   English syllables

  • croup — croup1 [kro͞op] n. [< obs. or dial. croup, to speak hoarsely, of echoic orig.] a condition resulting from any obstruction of the larynx, esp. an inflammation of the respiratory passages, with labored breathing, hoarse coughing, and laryngeal… …   English World dictionary

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