Spontaneous TR is a rare phenomenon in the pediatric population, but despite its rarity, it represents an important condition to be aware of in children because prompt appropriate treatment can be lifesaving [
1,
2]. Spontaneous TRs are believed to result from raised intratracheal pressure against a closed glottis, such as for severe coughing, and occur especially at the lower third of the trachea and the cricothyroid membrane [
1,
2]. The laceration usually extends longitudinally in the posterior membranous wall of the trachea or involves the junction between the membranous wall and cartilaginous ring [
2]. In accordance with these considerations, the rupture in our case was located in the right lower third of the posterior membranous tracheal portion, although the child’s parents did not report severe coughing episodes. Coughing is the most efficient mechanism for clearing mucus and fluid secretions from the airways. The total amount of mucus in the conducting airways is determined by the rate of secretion and the clearance of mucus by epithelial reabsorption, evaporation, ciliary movement, and cough transport [
3]. When coughing is weak, bronchial secretions can accumulate to the point that they obstruct airflow and mucous plugging occurs and, if it cannot be cleared, the situation can be serious, as in our case. [
4]. The magnitude of the cough reflex is influenced by both the site of stimulation and the central nervous state [
5]. Laryngeal and tracheal stimulation causes vigorous respiratory responses, while the irritation of bronchi, bronchioles, and alveoli determines little or no effective cough reflex [
4,
5]. Studies of anesthetized humans have shown that the cough reflex is suppressed [
4‐
6]. In accordance with this, some adult cases have been described in the English literature of sudden lung collapse or segmental acteletasis, with or without pneumomediastinum due to mucous plug formation, that occurred during and after general anesthesia because of weak cough reflex [
7‐
9]. Similarly, sleep is also known to suppress the cough reflex, especially during rapid eye movement (REM) sleep, and some studies demonstrated that irritant stimuli can cause coughing only if the stimulus first produced arousal, but the biological mechanisms for this action are poorly understood [
4,
5]. To the best of our knowledge, lung atelectasis due to mucous plug formation during nighttime sleep and manifesting as TR has not yet been described. In our case, the child’s parents did not notice nor complain of cough during the child’s nighttime sleep and, at the time of hospital admission, they recounted that the child slept well. However, before his nighttime rest our little patient had some weak coughing episodes, probably indicating an underlying irritative cause – that remained unknown – which could have produced mucous bronchial hypersecretion. We could hypothesize that during the nighttime, the collection of secretions in the peripheral airways and the sleeping state may have lead to ineffective cough reflex, so the child had an uninterrupted sleep probably without agitation and changes of decubitus. Thus the secretions became stagnant and accrued in the mainstream bronchi, forming a mucous plug. The mucous plug and the suppressed cough reflex played a synergetic effect, amplifying the extent of bronchial lumen obstruction, causing lower lobe atelectasis of his left lung. When the child awoke, the cough reflex resulted in a few effective and tussigenic paroxysmal attacks, not noticed by the child’s parents, which caused TR during the compressive coughing phase, when the glottis closes and forced expiration with a rapid rise in intrathoracic pressure takes place. Then the air leaking from a TR spread throughout in the soft tissue planes of his neck, retropharynx, pericardium, mediastinum, spinal canal, and pleural space, resulting in subcutaneous emphysema and respiratory distress at the moment of the child’s admission to our hospital. Starting from the first report of spontaneous TR in a 7-year-old boy with acute tracheobronchitis by Roh and Lee, only another four reports have been described in the English literature, including cases respectively associated with paroxysmal productive coughing in a 14-year-old boy, with presumptive anaphylaxis and no pathology revealed by bronchoscopy in a 3-year-old boy, with violent vomiting in a 4-year-old girl, and with a 2-day history of severe coughing in an 18-month-old boy [
1,
2,
10‐
12]. To the best of our knowledge, this is the first reported case of spontaneous TR secondary to nocturnal obstructive atelectasis by secretions and mucous plug in an otherwise healthy child. Even though rare, TR should be considered the cause of respiratory distress when clinical examination and CXR reveal signs of nonextended lung obstructive atelectasis despite important air leakage in the soft tissue planes.
CXR is the initial imaging examination in the diagnostic process to also investigate the presence of pneumothorax, which is one of the initial presumptive diagnoses in case of neck and thorax subcutaneous emphysema, but it does not allow the direct detection of tracheal injuries. CT is more sensitive for detecting TR or related complications, for evaluating the extent and localization of air collections, and it also makes possible the assessment of underlying pulmonary disease. In our case, CT was able to demonstrate the presence of a short tracheal tear associated with complete lower lobe atelectasis of the left lung without air bronchogram. The definitive diagnosis should be reached by using fiberoptic endoscopy, which must be performed as soon as possible if there is any question of an airway rupture because TR is potentially lethal [
2]. In our case, the longitudinal TR was diagnosed on both CT and endoscopic examination. Moreover, bronchoscopy showed mucoid impaction in the lower lobe of the left lung, allowed the removal of the mucous plug, and the aspiration of the bronchial secretions. Following this, the child had marked improvement in his oxygenation and ventilation, and his left lung expanded after the plug was removed. During follow-up, serial CXRs are considered to be sufficient for evaluating the resolution of the air collections, as in our case. Generally, localized short (<2 cm) lacerations can be treated conservatively with empiric broad-spectrum antibiotic therapy and intubation with the cuff inflated distally to the tear to prevent further air leakage through the injury site. Otherwise surgical repair is preferred [
2]. In our patient, the tracheal longitudinal tear was short and the child’s clinical condition clearly improved after therapeutic bronchoscopy, consequently the TR was managed conservatively.