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 extracts 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 40 degrees C and afterward, one of them was boiled for 15 minutes. Thirty-three of these patients underwent oral challenges with lentils and three had a convincing recent history of lentil anaphylaxis. RESULTS: Twenty patients had a positive oral challenge; 13 were negative. Skin prick tests performed with the boiled extract at 0.5 and 5 mg/mL were positive in 96% and 100% of patients with positive food challenge, and in 31% and 85% of those with negative food challenge, respectively; positive skin test results were similar in both groups using the crude extract. Mean wheal sizes using the boiled extract at 0.5, 5, and 10 mg/mL were significantly 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, respectively; P < 0.05) These mean values were not statistically different using the crude extract. CONCLUSIONS: These data suggest that lentil extracts for the diagnosis of lentil hypersensitivity should be heated, since boiled extracts, used at a concentration of 0.5 or 5 mg/mL, best identify clinically sensitive individuals.