Review Question - QID 215056

A 26-year-old woman presents to the clinic with diarrhea, bloating, flatulence, and abdominal cramps. These symptoms have been going on for 2 months. She has lost 6 pounds (2.7 kg) over these 2 months. Her medical history is significant for mild intermittent asthma for which she uses an albuterol inhaler as needed. She is sexually active with 1 male partner. She recently returned from South India following a mission trip for 6 weeks. Her temperature is 98.6°F (37.0°C), blood pressure is 105/70 mmHg, pulse is 95/min, and respirations are 14/min. On examination, the patient’s skin is pale. Labs are obtained and show the following results:

Leukocyte count: 4,500/mm^3
Hemoglobin: 10.5 g/dL
Platelets: 110,000/mm^3
Mean corpuscular volume (MCV): 116 µm^3
Reticulocyte count: 0.5%

A biopsy of the small bowel reveals blunting of villi and a mixed infiltration of lymphocytes, plasma cells, and eosinophils. Which of the following is the most likely diagnosis?