A 20-year-old man comes to the physician because of a 3-month history of dysphagia, food impaction, and chest pain after eating. He has also lost 10 kg of weight since the onset of symptoms. He has no history of asthma or atopic dermatitis. Heart rate is 75 bpm, blood pressure is 104/64 mm Hg, and physical examination shows no abnormal findings. Endoscopy shows an inflamed esophagus with mucosal edema and multiple whitish papules. Histology shows eosinophilic microabscesses. Which of the following is the most likely diagnosis?