Laryngeal and Tracheal Infection

Original article by Tom Leach | Last updated on 27/5/2014
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Introduction

Although sometimes referred to as synonymous as Croup’ there can be many causes, croup just being the most common. It can be a very serious acute situation, as inflammation can rapidly block the upper airway.
 
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
 

Causes

Croup: -
  • 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
 

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
 

Croup

  • 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.

Management

  • 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!

Presentation

  • 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!
 

Treatment

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

 
Croup
Epiglottitis
Onset
Days
Hours
Preceding Coryza
Yes
No
Able to drink
Yes
No
Drooling
No
Yes
Appearance
Unwell
Toxic, very ill
Fever
<38.5’
>38.5’
Stridor
Harsh rasping sound
Soft ‘whispering’
Voice
Hoarse
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.

Presentation

  • 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
 

Diagnosis

  • Swab and PCR of the material around the fauces.
 

Treatment

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