Wherever children are encountered medically – in the doctor’s surgery, in the emergency services and in hospital – breathing sounds are one of the most important symptoms and can be of no or considerable significance.

1. fundamentals and acute events

All newborns and infants have audible breathing with typical nasopharyngeal, i.e. close to a soft snoring sound, which often confuses parents and caregivers without experience with newborns.
An experienced person should be asked to assess this at least once. NOTE: If you are thinking about a bronchoscopy, you should have it done!
A functional and anatomical examination (spontaneously breathing + at rest) is required for a complete diagnosis The following typical differential diagnoses result from the constellation of the type of stridor and medical history.
However, because there is usually a discrepancy between the symptoms and the nature, severity and significance of the underlying causes, a bronchoscopy with functional and anatomical examination of the airways should be performed without hesitation!
No other examination method is suitable for making a diagnosis and thus possibly ruling out a significant threat.
The term “true” stridor refers to an amplified respiratory sound that can be heard without aids and is caused by turbulent airflow at narrow points in the airways.
The first step is to assess the quality of the sound and take a thorough medical history.
Far too often – and usually incorrectly – stridor in newborns and small infants is postulated to be tracheomalacia!
The following typical differential diagnoses (and many very rare diagnoses that cannot all be listed here) result from the constellation of the type of stridor and the medical history. Sudden onset of breath sounds indicates an acute event, the most important diagnoses are as follows.
A sudden onset of respiratory distress with expiratory stridor and delay in expiration suggests asthma in particular.
The smaller the child, the more valuable the examination is, in addition to auscultation, by placing the hands on the thorax: spasms, secretions, breathing patterns and congestion can be felt and localized.
The therapeutic procedure with regard to inhalation therapy hardly differs from the adult (Table 1).
The sudden onset of inspiratory stridor with a barking cough is usually croup syndrome, which occurs most frequently in the context of viral infections but also spontaneously and is caused by subglottic swelling of the mucous membrane.
This disease rarely becomes threatening and can be treated in the same way as asthma.
However, differential diagnoses include tracheitis and epiglottitis (see below).
Especially in the absence of vaccinations and a progression of hoarseness, inspiratory stridor and barking cough – which can typically be triggered by pressing a spatula on the tongue – diphtheria, which used to be called “true croup”, should also be considered. Table 1: Drug therapy for asthma attacks or pseudo-croup (from [1]).