Are double-blind food challenges necessary before starting an elimination diet?
Food allergy is normally treated by eliminating the offending food. Such a measure, however, may cause nutritional and sociopsychological problems, so an allergy must be diagnosed with the utmost certainty. To date the most reliable diagnostic test is the double-blind food challenge (DBFC). The rationale for using this test is the marked difference in positive results with open and double-blind food challenges. Only about 30% of open challenges that appear positive are confirmed on blind challenge. There is ample evidence, too, that a negative DBFC may in fact indicate tolerance to that food. From the literature it appears that almost all patients who reintroduced a certain food into their diet after a DBFC had given negative findings did not present any adverse reaction to it. In our caselist of 21 patients with probable reactions to foods but negative DBFC, 19 (90.5%) tolerated the “incriminated” food well when it was reintroduced into their diet even in unlimited amounts. Only two (
