Food hypersensitivity reactions visualised by ultrasonography and magnetic resonance imaging in a patient lacking systemic food-specific IgE.

BACKGROUND Abdominal complaints related to food intake might be due to hypersensitivity. A firm diagnosis of food allergy is often difficult to establish, particularly in the absence of systemic food-specific IgE. Using ultrasonography and magnetic resonance imaging (MRI) we were able to visualise the intestinal response in one such case. METHODS A 24-year-old female presented with self-reported food hypersensitivity, particularly related to the intake of egg. Nausea and diarrhoea were predominant symptoms. Double-blind placebo-controlled food challenge with raw egg was positive, but all other conventional tests of food hypersensitivity, including skin prick test, total and food-specific IgE in serum, were negative. A thorough investigation programme could not reveal any organic disease of the gastrointestinal tract. We extended the evaluation to include two new provocation tests, where intestinal wall thickening and the amount of luminal liquid were monitored by external abdominal ultrasound and MRI. RESULTS Both ultrasound and MRI investigations indicated intestinal wall thickening and influx of large amounts of fluid into the proximal small intestines within 10 min of duodenal challenge with egg. The response was associated with abdominal pain and bloating. CONCLUSIONS The response to provocation was typical of an immediate allergic reaction. Our results indicate that local food-induced hypersensitivity reactions can occur in the gut in the absence of systemic indications of IgE-mediated allergy. Abdominal ultrasonography and MRI might become valuable tools for documenting such responses.