Oral challenge with food additives

A randomized, placebo-controlled oral challenge with food additives (preservatives and food colorings) was carried out in 101 patients with eczema of undetermined origin who suspected that the intake of certain foods aggravated their dermatitis. 37 reacted to 1 or more of the food additives but not to a placebo, while 16 reacted to the placebo, or both the placebo and food additives. 48 had no reactions. The difference between the number of reactions to the food additives and the number of reactions to the placebo was not statistically significant. The reactions could be reproduced in only 1/3 of those challenged twice. It was not possible to correlate the reactions to food additives to reactivity to specific foodstuffs containing the same additives. If intolerance to food additives is suspected, an elimination diet seems warranted, regardless of whether the patient reacts to oral challenge with food additives.