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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.

Background/Aim: Subjective food hypersensitivity is prevalent in the general population. The aim of this study was to seek objective evidence of food hypersensitivity by analyzing intestinal permeability and inflammation markers in gut lavage fluid. Methods: Fifty-two patients with abdominal complaints self-attributed to food hypersensitivity were examined by skin prick test, serum IgE analysis, double-blind, placebo-controlled food challenge (DBPCFC), and intestinal lavage. The results were compared with those of 44 patients without food hypersensitivity. Neither the patients nor the controls had organic diseases that could explain their symptoms. Intestinal lavage was performed by administering 2 liters of isotonic polyethylene glycol (molecular weight 3,350 daltons) solution containing 50 µCi of [51Cr]EDTA through a nasoduodenal tube. The first clear fluid passed per rectum was collected and analyzed for histamine, eosinophilic cationic protein (ECP), tryptase, and calprotectin. The intestinal permeability was assessed by determining the 5-hour urinary excretion of [51Cr]EDTA. Calprotectin was also analyzed in native faecal samples. Results: The ECP concentration in gut lavage fluid was significantly higher in the patients than in the controls (p = 0.007), but the overlap between groups was large. Food hypersensitivity was confirmed by positive DBPCFC in only 4 patients. On average, histamine and ECP concentrations were high in these patients. Tryptase, intestinal permeability, and faecal and lavage calprotectin levels were normal. Conclusions: Very few patients had objective evidence of food hypersensitivity. Analyzing intestinal permeability and inflammation markers in gut lavage fluid did not contribute to the diagnosis, but further studies on histamine and ECP are warranted.