P0904 - Watch Out for Asthma Mimickers: Teenager with Persistent Cough

Introduction: Asthma is the most common chronic disease of childhood. However, pediatricians should be aware of potential mimickers of asthma, which can have serious consequences.

Case: We present the case of a 16 year-old female with persistent cough who was previously diagnosed with poorly controlled asthma. Despite escalating inhaled corticosteroid therapy, she had increasingly frequent respiratory exacerbations with wet cough and dyspnea over the preceding 2 years. Auscultation revealed diminished breath sounds at both lung bases. A previous chest radiograph had shown hyperinflated lungs and findings compatible with reactive airway disease. Spirometry showed an obstructive picture with some bronchodilator reversibility. She was prescribed a 5-day course of systemic steroids with no significant improvement. Repeat spirometry showed fixed irreversible obstruction without significant improvement from prior study and on further history she also had dysphagia with solid foods and infrequent emesis. Subsequent chest CT revealed a severely dilated esophagus throughout the entire length, with maximal measurements of 60 mm x 35 mm (transverse x anteroposterior) concerning for achalasia with evidence of adjacent tracheal compression and main-stem bronchi narrowing. Lung parenchyma showed diffuse ground-glass opacities, greater on the right, suggestive of recurrent aspiration. Patient was admitted for further management which included esophagogastroduodenoscopy (EGD) with endolumenal functional lumen imaging probe (EndoFLIP). After removal of fluid and food, the esophagus showed decreased distensibility with absent contractility consistent with Type I Achalasia. Patient underwent per oral endoscopic myotomy (POEM) with improvement in distensibility of the lower esophageal sphincter. At her 6-month follow-up appointment, patient reported complete resolution of her cough and dysphagia.

Discussion: Primary esophageal achalasia is a neuromuscular disorder resulting from impaired relaxation of the lower esophageal sphincter (LES) with subsequent loss of peristalsis in the distal esophagus. It occurs rarely in pediatric patients with an annual incidence rate of approximately 0.11 per 100,000 children. As such, the diagnosis is often delayed or missed in this population. Presenting symptoms commonly include dysphagia, regurgitation, and weight loss. Respiratory symptoms can infrequently develop due to tracheal compression from the enlarged esophagus as well as aspiration of esophageal contents. Pulmonary function tests were diagnostic in this patient.

Conclusion: A high index of suspicion is required in a patient with difficult to control asthma. This case report illustrates the importance of thorough history and exam leading to pulmonary function tests in alerting to the possibility of tracheal obstruction causing asthma-like symptoms. The differential diagnosis of cough should be expanded when respiratory function tests fail to improve with bronchodilators or steroids.