A potential diagnostic method for food allergy: clinical application and immunogenicity evaluation of an elemental diet.

The use of a simple, hypoallergenic elemental diet would appear well suited for diagnosing food allergy. Vivonex was used in 21 patients (5 to 40 years old) suspected of food allergy or those who had failed to respond to the usual management of inhalant allergy. To study immunogenicity, five New Zealand rabbits were immunized with Vivonex, milk, and egg and were evaluated for the production of precipitin and passive cutaneous anaphylactic antibodies, the latter was evaluated in three Hartley guinea pigs. The clinical study was conducted over a 2- to 3-week period with evaluation of symptom and medication scores, physical examination, and hematological and biochemical measurements made before and after the Vivonex trial, which was a minimum of 1 week. No consistent, significant improvement of allergic manifestations were seen while patients received Vivonex. On the other hand, there were no serious side effects noted either clinically or by laboratory measurements, although four patients discontinued the study because of Vivonex palatibility. Vivonex was not immunogenic by either the precipitin reaction or passive cutaneous anaphylactic response. Although Vivonex did not prove helpful in these severe, refractory allergic individuals, we were encouraged by its safety and acceptance in the outpatient setting. Further studies in young allergic children who are more likely to have clear-cut food sensitivity are being planned.