A 4-month-old boy is brought to the office for follow-up after a recent urgent care visit to evaluate noisy breathing. The noisy breathing began shortly after birth and worsens when he cries or eats. He was given an inhaled bronchodilator and oral corticosteroid but there has been no improvement. The patient is fed cow's milk-based formula and feeding seems to tire him, so it takes about 40 minutes to finish each bottle. He has normal-appearing stools daily. The patient was born at 37 weeks via spontaneous vaginal delivery. He is at the 20th percentile for height and weight. He attends daycare, his parents are nonsmokers, and they have a cat. The patient is afebrile with normal vital signs. Physical examination shows biphasic stridor that is louder on exhalation. The stridor improves with extension of the neck but does not improve with prone positioning. There is no cough, rhinorrhea, or skin changes. Which of the following is the most likely cause of this patient's symptoms?

Question

A 4-month-old boy is brought to the office for follow-up after a recent urgent care visit to evaluate noisy breathing.  The noisy breathing began shortly after birth and worsens when he cries or eats.  He was given an inhaled bronchodilator and oral corticosteroid but there has been no improvement.  The patient is fed cow's milk-based formula and feeding seems to tire him, so it takes about 40 minutes to finish each bottle.  He has normal-appearing stools daily.  The patient was born at 37 weeks via spontaneous vaginal delivery.  He is at the 20th percentile for height and weight.  He attends daycare, his parents are nonsmokers, and they have a cat.  The patient is afebrile with normal vital signs.  Physical examination shows biphasic stridor that is louder on exhalation.  The stridor improves with extension of the neck but does not improve with prone positioning.  There is no cough, rhinorrhea, or skin changes.  Which of the following is the most likely cause of this patient's symptoms?

Quizplus · Accepted Answer

11ec25c8_d63c_ac82_bc81_67984ef2f315_MD0003_00 Vascular rings encompass a variety of congenital malformations of the aortic arch system that encircle the trachea and/or esophagus and cause varying degrees of compressive symptoms. Patients develop respiratory symptoms because the ring causes external tracheal compression, resulting in a fixed airway obstruction that leads to biphasic stridor that worsens with increased work of breathing (eg, crying, feeding). Patients often extend the neck because it improves stridor by decreasing tracheal compression. Some patients may also develop esophageal compression symptoms, including vomiting and solid food-predominant dysphagia. esophageal compression Diagnosis can be made with a CT scan to delineate the precise anatomy forming the vascular ring and evaluate any associated tracheal abnormalities. Due to possible concurrent cardiac and airway abnormalities, all patients require direct laryngoscopy, bronchoscopy, and echocardiogram. Treatment is surgical division of the structures creating the ring. (Choice B) Cow's milk allergy (eg, caused by the introduction of cow's milk protein-based formula) can present with an array of IgE-mediated and non-IgE-mediated reactions including eczema, vomiting, bloody stools, and failure to thrive. Respiratory symptoms would be rare, particularly in isolation. (Choice C) Aspiration of a foreign body in the upper airway (eg, larynx) could cause stridor but would also likely cause life-threatening, acute respiratory distress. A chronic foreign body in the lower airways (eg, bronchi) does not typically cause stridor but can present with recurrent pneumonia that improves symptomatically but still has persistent radiographic changes. (Choices D and E) Laryngotracheobronchitis (croup), a viral infection leading to subglottic edema, and epiglottitis, a bacterial infection of the epiglottis, both threaten the upper airway and can therefore cause stridor and retractions that improve with exaggerated extension of the neck (eg, tripod position). In contrast to this patient, those with croup or epiglottitis present more acutely and have associated infectious symptoms (eg, fever, pharyngitis). tripod position Educational objective: Vascular rings are congenital malformations of the great vessels that encircle and compress the trachea and/or esophagus. Respiratory symptoms may include biphasic stridor that improves with neck extension. Esophageal symptoms include dysphagia, vomiting, and difficulty feeding. References: The presentation and management of vascular rings: an otolaryngology perspective. (http://www.ncbi.nlm.nih.gov/pubmed/17034866) Congenital vascular rings: a clinical challenge for the pediatrician. (http://www.ncbi.nlm.nih.gov/pubmed/25604054) Vascular rings. (http://www.ncbi.nlm.nih.gov/pubmed/27301603)

A 4-Month-Old Boy Is Brought to the Office for Follow-Up