A previously fit and well 52-year-old man presented to the hospital with a 3-month history of refractory heartburn and progressive weight loss (5 kg). After an initial response to empiric treatment with 20 mg omeprazole daily, heartburn relapsed and became refractory to proton pump inhibitor. His past medical history and physical examination were unremarkable. Upper endoscopy showed a thick white membrane in the distal part of the oesophagus, crossing the gastro-oesophageal junction (figure 1A); the mucosa surrounding the distal margin was slightly depressed but not reddened. An initial diagnosis of candidosis was suggested and the patient …