Methods: A retrospective study done in the department of Pediatric Allergy of a Children’s Hospital from June 2008 to May 2011. Data was taken from the records of 100 patients who gave positive to Prick and Prick-to-Prick food tests. We also looked for the clinical setting referred to by the patient. The frequency and IC 95% were analyzed by Chi2. Out of the 100 patients, 48 were female and 52 male. These patients were grouped by age range. Fifteen patients fall within 1 to 2 years range, 15 patients fall within the 3 to 5 year range and 26 patients within the over-six-years range. Twenty patients presented asthma, 16 allergic rhinitis, 24 atopic dermatitis, 33 food allergy, 5 gastrointestinal eosinophilia and 2 children presented other reactions. The tests were done with extracts of IPI ASAC Laboratories and fresh food. We considered that the tests that were positive were those with a wheal diameter greater than 3 mm over the negative control.
Results: 10%(IC 95% 4.12-15.88) of the patients had a reaction after the Prick test and presented clinical symptoms of which 30% were cutaneous and 70% gastrointestinal. Thirty six percent of the patients had a reaction after the Prick-to-Prick test(95% CI 26.59-45.40)[p = 0.005] of which 17% developed respiratory symptoms, 22% skin, and 61% gastrointestinal. The main fresh foods with which the patients gave positive were: milk 16%(95% CI 8.81-23.18), egg 10%(95% CI 4.12-15.88), and wheat 7%(95% CI 1.99-12.00). Prick tests like milk, eggs and corn could not be assessed properly by the sample size.
Conclusions: Prick-to-Prick tests are more effective than Prick to detect patients with food clinical reactions.