Review Question - QID 214555

A 12-year-old-boy is brought to the pediatrician by his mother for a sore throat and chronic cough. He has had the cough for years, but recently he began coughing up “phlegm.” The patient also reports dry skin, dry eyes, trouble seeing at night, night sweats, and fatigue. His mother states that she has noticed weight loss. The patient recently immigrated from Brazil. He has a history of multiple sinus infections and chronic diarrhea. He has been hospitalized twice for pneumonia. He takes no medications. His mother states he is up to date on all his vaccinations including bacilli Calmette-Guerin (BCG) vaccine. On examination, there are nasal polyps and bilateral pulmonary crackles and wheezes. Which of the following is the most likely cause for this patient's symptoms?