A 4-year-old boy is brought to the office for difficulty breathing through his nose. The issue started 6 months ago and has progressively worsened. Since his adoption at age 6 months, the patient has had recurrent epistaxis and numerous courses of antibiotics for sinus infections and pneumonia. Weight and height are at the 3rd and 5th percentiles, respectively. Temperature is 38.9 C (102 F), blood pressure is 100/70 mm Hg, pulse is 112/min, and respirations are 24/min. Pulse oximetry reveals an oxygen saturation of 93%. Physical examination shows a thin boy with audible nasal breathing and bilateral nasal polyps. The oropharynx is clear, and the neck is supple. Cardiac examination is unremarkable. Lung auscultation reveals diffuse, coarse crackles. The abdomen is soft with no organomegaly. Pulses are strong, and digital clubbing is present. Which of the following is the most likely diagnosis in this patient?

Question

A 4-year-old boy is brought to the office for difficulty breathing through his nose.  The issue started 6 months ago and has progressively worsened.  Since his adoption at age 6 months, the patient has had recurrent epistaxis and numerous courses of antibiotics for sinus infections and pneumonia.  Weight and height are at the 3rd and 5th percentiles, respectively.  Temperature is 38.9 C (102 F), blood pressure is 100/70 mm Hg, pulse is 112/min, and respirations are 24/min.  Pulse oximetry reveals an oxygen saturation of 93%.  Physical examination shows a thin boy with audible nasal breathing and bilateral nasal polyps.  The oropharynx is clear, and the neck is supple.  Cardiac examination is unremarkable.  Lung auscultation reveals diffuse, coarse crackles.  The abdomen is soft with no organomegaly.  Pulses are strong, and digital clubbing is present.  Which of the following is the most likely diagnosis in this patient?

Quizplus · Accepted Answer

11ec25c8_d717_7bc4_bc81_2dc0389636fe_MD0003_00 Cystic fibrosis (CF) is an autosomal recessive disorder caused by a mutation in the CF transmembrane conductance receptor (CFTR) gene. Defective chloride transport via CFTR causes the accumulation of thick, dehydrated mucus in the respiratory tract, which allows bacteria to proliferate and invade the sinuses. Most cases are identified on newborn screening; however, because screening does not detect less common CFTR mutations, a minority of cases are not identified until the patient is symptomatic. Detection of an elevated sweat chloride concentration is diagnostic. CFTR Characteristic findings of CF include recurrent sinopulmonary infections and digital clubbing due to chronic hypoxia. Virtually all patients with CF develop chronic rhinosinusitis. Up to one-third have nasal polyps, benign outgrowths of inflamed mucosa that form as a result of chronic infection and appear as shiny, grey masses. Polyps obstruct the nasal passages and exacerbate sinusitis; management includes intranasal glucocorticoids (for symptomatic relief) and, in some cases, surgical resection. In addition to the respiratory features, pancreatic insufficiency leads to malabsorption, resulting in poor growth and deficiency of the fat-soluble vitamins A, D, E, and K (eg, epistaxis). digital clubbing (Choice B) Eosinophilic granulomatosis with polyangiitis (formerly Churg-Strauss syndrome) is a systemic vasculitis characterized by chronic rhinosinusitis, including nasal polyps, asthma, and prominent eosinophilia. It is typically diagnosed in adulthood, and diffuse wheezing (not crackles) would be expected. (Choice C) IgA plays a significant role in mucosal immunity in the respiratory and gastrointestinal tracts. Patients are typically asymptomatic with IgA deficiency, although recurrent bacterial sinopulmonary infections can occur. Digital clubbing and failure to thrive are unlikely manifestations. (Choice D) Severe allergic rhinitis can predispose patients to epistaxis as well as recurrent sinusitis and nasal polyposis; however, lung disease with chronic hypoxia, rales, and digital clubbing is not expected. (Choice E) Severe combined immunodeficiency usually results from X-linked mutations that lead to recurrent severe infections, poor growth, and chronic diarrhea. Infants who do not undergo hematopoietic stem cell transplantation usually die from fulminant infections before age 12 months. Educational objective: Not all patients with cystic fibrosis are identified through newborn screening. Therefore, the presence of nasal polyps, recurrent sinopulmonary infections, digital clubbing, and signs of pancreatic insufficiency (eg, poor growth, deficiency of fat-soluble vitamins) should prompt an evaluation. References: Chronic rhinosinusitis in patients with cystic fibrosis. (http://www.ncbi.nlm.nih.gov/pubmed/27393775) Pediatric nasal polyps in cystic fibrosis. (http://www.ncbi.nlm.nih.gov/pubmed/27329094)

A 4-Year-Old Boy Is Brought to the Office for Difficulty