Laryngeal and Tracheal Infection
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Although sometimes referred to synonymously as croup’ there can be many causes of laryngeal and tracheal infection, croup just being the most common. It can be a very serious acute situation, as inflammation can rapidly block the upper airway, leading to respiratory arrest and death if untreated.
The main features of this are:
  • Stridor – (inspiratory wheeze) – rasping sound
  • Hoars voice – due to inflammation of the vocal
  • Barking cough – some say it sounds like a sea lion!
  • Dyspnoea


  • Viral laryngotracheitis – VERY COMMON! – accounts for 95% of cases
  • Bacterial Tracheitis (rare)
Rare causes:
  • Epiglottitis
  • Inhalation of smoke/hot fumes
  • Trauma
  • Retropharyngeal abscess
  • Allergic laryngeal oedema (angioedema)
  • Tetany – poor vit D intake
  • Measles
  • Diphtheria


  • Can be diagnosed clinically, but an x-ray may be performed – particularly if there is a possibility of foreign body
  • The steeple sign may be seen on AP x-ray in croup. This is caused by glottic and subglottic swelling of the trachea. It is so called becasue as the air-filled trachea is narrowed by swelling – it resembles the shape of a church steeple on x-ray
The steeple sign seen in croup
The steeple sign seen in croup

Assessing Severity

This is done by measuring the degree of subcostal, intersternal and sternal recession. This can be present (in order of increasing severity):
  • Not at all
  • Only on crying
  • At rest
  • Biphasic
Other features that indicate severe respiratory distress include:
  • Central cyanosis
  • Rapid heart rate
  • Agitation
  • Low O2 saturation – should be measured by pulse oximetry

Acute management

  • DONT EXAMINE THE THROAT! – this can precipitate a complete obstruction
  • Careful observations for deterioration
  • If you are worried, give nebulised epinephrine – (usually when O2 <93%)
  • Consider steroids (oral or nebulised)
  • If respiratory failure develops, then INTUBATE! – This is now rare due to steroid treatments


  • Occurs between ages 2-6. Peak incidence age 1-2.
  • 5% of children will be affected at some stage
  • Initially – symptoms like the common colde.g. fever and coryza. Symptoms may initially only be at night, and are generally worse at night.
  • SRIDOR may be present. This can make the child worried, and may exaggerate hyperventilation
  • The volume of stridor can also indicate the severity of the respiratory distress. In severe disease, stridor may be quiet, due low respiratory flow
  • Barking cough
  • Mucosal inflammation and increased secretions. These affect the larynx, trachea and bronchi. The subglottal region is the most likely to cause obstruction.
  • Mild cases (e.g. costal recession not apparent at rest) may be managed at home, although the younger the child (i.e. <12 months) the more likely they are to be admitted.
  • Steam and warm air – is often recommended although of no proven benefit.


  • Oral and nebulised steroids (dexamethasone, prednisolone) and nebulaised steroids are proven to reduce the length and severity of the attacks.
  • If stable, you can probably send the patient home, and tell the parents to watch out for ↑respiratory rate, restlessness and fatigue.
  • Nebulised epinephrineshould be given to those with O2 sats of <94%


Bacterial Tracheitis

Presentation similar to viral croup, except more rapidly progressive, and high fever likely. Commonly caused by S Auerues and H Influenzae.
Mucous secretions are likely to be thicker and greater in volume.
  • Caused by H influenzae (type B). It is life threatening. Incidence is relatively low in the UK due to the Hib immunisation system.
  • There is massive swelling of the epiglottis and associated tissues. There is also often septicaemia.
  • Can occur at any age, most common age 1-6
  • Important to differentiate form croup as treatment is very different!


  • High fever
  • Child appears very ill / toxic
  • STRIDOR – may be present
  • Very painful – this can prevent swallowing, and the child may drool
  • Rapid onset / rapid increasing symptoms over several hours
  • Child likes to sit upright with mouth open, as this provides the best position to keep the airway open.
  • No cough
  • Lying down, or examination of the throat with a tongue depressor can be life-threatening and should not be performed!
  • The red swollen epiglottis may be visible above the back of the tongue is some cases (rising sun sign) – but don’t examine for it, or you may precipitate complete obstruction!


Give general anaesthetic and intubate.
  • Don’t take blood cultures until intubation is complete
  • In some cases, the trachea may be so narrowed that intubation is not possible. Emergency tracheostomy may be required in these instances
Take blood cultures, and start a broad spectrum IV antibiotics, e.g. cefuroxime.

Usually, intubation can be stopped after 24 hours, and antibiotics should be continued for 3-5 days. Most children will be symptomless after 2-3 days, and there are usually no long-term problems.

  • In cases that cannot be extubate within 24 hours, the cause is usually bacterial, and it is not a true epiglottitis.
  • Rifampicin is offered to close household contacts as prophylaxis. This is standard procedure in all cases of Hib infection.
Vaccination schedule for Hib – this requires 4 vaccines:
  • 2 months
  • 3 months
  •  4 months
  • 12 months

Differentiating Croup for Epiglottitis

Preceding Coryza
Able to drink
Toxic, very ill
Harsh rasping sound
Soft ‘whispering’
Muffled, child won’t speak

Papilloma of the larynx

(aka laryngeal papillomatosis)
A papilloma is a benign epithelial tumour, which grows perpendicular to the epithelium, in finger-like projections, and may obstruct lumen – in this case, the larynx.
This condition is twice as common in children as adults, but is still rare (2-4 per 100 000). The tumours usually regress spontaneously at around the time of puberty.
It can be fatal if the growths obstruct the larynx completely.
Like many papillomas, it is caused by HPV (Human papilloma virus), and the tumours themselves are benign.
Treatment nearly always involve surgery. This is usually by laser ablation. The surgeon must be careful, as the tumour is very easily spread, for example, on tracheostomy, the tumours may grow around the stoma after surgery!
This is caused by the toxin of the bacterium Corynebacterium Diphtheriae.


  • Swollen tonsils
  • Membrane over the back of the palate (fauces)
  • Polyneuritis – often involves the cranial nerves
  • Shock
  • Dysphagia
  • Muffled voice
  • Cough
  • Airway obstruction
  • Bronchopneumonia
  • Myocarditis – do regular ECG’s on all diphtheria patients


  • Swab and PCR of the material around the fauces.


  • Diphtheria antitoxin, plus
  • Erythromycin
  • Give all close contacts 7 days of erythromycin prophylaxis.



  • Murtagh’s General Practice. 6th Ed. (2015) John Murtagh, Jill Rosenblatt
  • Oxford Handbook of General Practice. 3rd Ed. (2010) Simon, C., Everitt, H., van Drop, F.
  • Beers, MH., Porter RS., Jones, TV., Kaplan JL., Berkwits, M. The Merck Manual of Diagnosis and Therapy

Read more about our sources

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Dr Tom Leach

Dr Tom Leach MBChB DCH EMCert(ACEM) FRACGP currently works as a GP and an Emergency Department CMO in Australia. He is also a Clinical Associate Lecturer at the Australian National University, and is studying for a Masters of Sports Medicine at the University of Queensland. After graduating from his medical degree at the University of Manchester in 2011, Tom completed his Foundation Training at Bolton Royal Hospital, before moving to Australia in 2013. He started almostadoctor whilst a third year medical student in 2009. Read full bio

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