The diagnostic value of crude or boiled extracts to identify tolerant versus nontolerant lentil-sensitive children

Objective: The aim of this study was to compare two types of lentil extract s for use in skin prick tests for the diagnosis of lentil clinical allergy. Methods: Thirty-six patients with a history of allergic reactions after the ingestion of lentils were skin tested with two types of lentil extracts at 0.05, 0.5, 5, and 10 mg/mL. Both extracts were extracted at 4 degrees C an d afterward, one of them was boiled for 15 minutes. Thirty-three of these p atients underwent oral challenges with lentils and three had a convincing r ecent history of lentil anaphylaxis. Results: Twenty patients had a positive oral challenge; 13 were negative. S kin prick tests performed with the boiled extract at 0.5 and 5 mg/mL were p ositive in 96% and 100% of patients with positive food challenge, and in 31 % and 85% of those with negative food challenge, respectively; positive ski n test results were similar in both groups using the crude extract. Mean wh eal sizes using the boiled extract at 0.5, 5, and 10 mg/mL were significant ly greater in patients with a positive oral challenge than in those with a negative one (4.9, 6.8, and 7.4 mm versus 1.9, 3.5, and 5.1 mm, respectivel y; P < 0.05) These mean values were not statistically different using the c rude extract. Conclusions: These data suggest that lentil extracts for the diagnosis of l entil hypersensitivity should be heated, since boiled extracts, used at a c oncentration of 0.5 or 5 mg/mL best identify clinically sensitive individua ls.