The Child with Stridor

Created on Fri, 04/14/2017 - 23:52
Last updated on Fri, 04/14/2017 - 23:55

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Question 27 from the first paper of 2016 was mainly about the handling of a paediatric airway, but the first half was also about stridor in children, and its causes. When you search for this as a string, usually four or five articles surface from the bubbling ooze of medical literature, of which for some reason three are usually different copies of Florence Cavanaghs' 1965 opus for the Proceedings of the Royal Society of Medicine. That's not a good reference. Of the current lietarture, the best single resource is probably a free copy of the 2016 article by Pfleger and Eber, if you can get a hold of it by nefarious means. An alternative might be the UpToDate article on this topic. Both of these recent resources were pillaged for information and used to construct the summary which follows.

Unfortunately, a discussion of the management of stridor depends extensively on where the stridor is coming from and what's causing it, and so this brief summary article cannot make any sensible attempt to address the management questions. All that can be done is the discussion of the various causes of stridor, and the arrangement and rearrangement of these causes into tables - according to the chronciity of the problem, the anatomical site of obstruction or vague aetiological categories. These different ways of representing the same thing should hopefully allow the trainees to settle on one specific method of remembering this information.  Some remember better when the causes are laid out according to a familiar mnemonic (VINDICATE, VITAMIN C etc) whereas others prefer to stroll anatomically through the airway, discussing the obstructions they encounter along the way.

Causes of stridor in children, according to timing of onset
Acute Subacute Chronic
  • Foreign body
  • Airway burns
  • Thermal epiglottitis
  • Caustic burns (ingestion)
  • Anaphylaxis
  • Epiglottitis
  • Laryngotracheitis (croup)
  • Retropharyngeal abscess
  • Peritonsillar abscess
  • Laryngomalacia
  • Tracheomalacia
  • Subglottic stenosis
  • Vocal cord dysfunction, Paradoxical vocal cord motion
  • Vocal cord paralysis
  • Vascular ring
  • Bronchogenic cyst
  • Laryngeal malformation
  • Infantile haemangioma
  • Tumour
  • Hypocalcemic laryngeal spasm
  • Recurrent respiratory papillomatosis
Causes of stridor according to anatomy of obstruction
Anatomical region Causes
Nose, pharynx
  • Choanal atresia
  • Choanal stenosis
  • Pierre Robin sequence
  • Craniofacial anomalies
  • Lingual thyroid and thyroglossal duct cyst
  • Hypertrophy of adenoids and/or tonsils
  • Retropharyngeal or peritonsillar abscess
  • Epiglottitis
  • Caustic or thermal airway burns
  • Tumour
Larynx
  • Laryngomalacia
  • Vocal cord paralysis
  • Subglottic stenosis (due to infection or trauma)
  • Laryngeal cyst
  • Laryngeal (laryngo-tracheo-oesophageal) cleft
  • Laryngeal web
  • Subglottic haemangioma
  • Lymphangioma
  • Laryngotracheitis (croup)
  • Supraglottitis
  • Respiratory papillomatosis
  • Hypocalcemic laryngeal spasm
  • Anaphylaxis
  • Hereditary angioedema
  • Inducible laryngeal obstruction
  • Foreign body aspiration
  • Vascular ring
  • Tumour
Trachea
  • Tracheomalacia
  • Bacterial tracheitis
  • Tumour
Causes of stridor arrayed by aetiology
Domain Causes
Vascular
  • Vascular ring
  • Haemangioma
Infectious
  • Epiglottitis
  • Laryngotracheitis (croup)
  • Retropharyngeal abscess
  • Peritonsillar abscess
  • Tracheitis
  • Recurrent respiratory papillomatosis (RRP)
  • Diphtheria
Neoplastic
  • Tumours at any level
  • Lymphadenopathy
Drug-induced
  • Anaphylaxis
  • Caustic ingestion
Idiopathic
  • Laryngomalacia
  • Tracheomalacia
  • Inducible laryngeal obstruction
  • Laryngeal cyst
  • Laryngeal web
  • Vocal cord paralysis
Congenital
  • Laryngeal (laryngo-tracheo-oesophageal) cleft
  • Craniofacial anomalies
  • Choanal atresia
  • Choanal stenosis
  • Pierre Robin sequence
Autoimmune
  • Hereditary angioedema
  • Anaphylaxis
Traumatic
  • Thermal burns
  • Post-traumatic subglottic stenosis
  • Foreign body
Endocrine
  • Hypocalcemic laryngeal spasm
Assessment of stridor: history, examination, labs and imaging
HISTORY
Age
  • Neonates and young infants: congential problems
  • Infants and toddlers: croup and foreign body
  • School-aged: abscesses and vocal cord dysfunction
  • All ages: anaphylaxis and tracheitis
Acuity
  • Hyperacute: anaphylaxis, angioedema
  • Acute: bacterial tracheitis or epiglottitis
  • Subacute: laryngotracheitis
  • Chronic: anatomical problem, eg. stenosis or neoplasm
Associated symptoms
  • Fever (infectious causes)
  • Drooling (supraglottic obstruction)
  • Muffled voice (supraglottic obstruction)
  • Cough (barking = croup)
  • Voice quality (vocal cord lesion)
  • Stridor during feeding (tracheo-oesophageal fistula)
  • Onset during activity (vocal cord dysfunction)
  • Urticaria (anaphylaxis)
  • Onset during sleep (spasmodic croup, tonsillar enlagement)
  • Altered mental state (cause of stridor, or consequence of hypoxia)
EXAMINATION  
General inspection
  • Failure to thrive (poor feeding, weight loss)
  • Congential abnormalities
  • "Funnel Chest" - pectus excavatum suggestive of chronic airway obstruction
Skin
  • Urticaria (anaphylaxis)
  • Haemangiomas (one may be in the airway
  • Cafe au lait spots (neurofibromatosis of the airway)
Posture
  • "tripid position" of epiglottitis
  • Cyanosis, hypoxia
Timing of stridor
  • Inspiratory: supraglottic onstruction
  • Expiratory: intrathoracic obstruction
  • Biphasic: fixed obstruction, or something in the glottis itself
  • "Stertor" - low pitched snoring sound, coming from an obstruction in the nasopharynx or oropharynx
LABORATORY TESTS
Infectious testing
  • FBC for WCC
  • Cultures
  • Nasal swabs for viral PCR (especially for parainfluenza types 1, 2, and 3)
Autoimmune
  • FBC for eosinophil count
  • Mast cell tryptase for anaphyalxis
  • Allergen testing
Endocrine
  • CMP: for calcium level
  • Vitamin D for rickets
IMAGING
Plain radiographs of the airway
  • Foreign body
CT of the neck and chest
  • Abscesses
  • Tumours
  • Fistulae
Video-nasendoscopy
  • Vocal cord dysfunction
  • Laryngomalacia
  • Foreign body retrieval

 

References

Cavanagh, Florence. "Stridor in children." Proceedings of the Royal Society of Medicine 58.4 (1965): 272.

Pfleger, Andreas, and Ernst Eber. "Assessment and causes of stridor." Paediatric respiratory reviews 18 (2016): 64-72.