Supplementary Material for: Asthmatic Response to Milk Ingestion Challenge in Adults: A Comparison of the Open and Double-Blind Challenges

Background: Cow’s milk allergy can participate in pathophysiological mechanisms underlying bronchial asthma in some adult patients. This role should ultimately be confirmed by means of a milk ingestion challenge. In this study, the diagnostic value of the open food ingestion challenge (OFICH) and the double-blind placebo-controlled food challenge (DBPCFC) techniques with milk were compared in adult patients suffering from bronchial asthma with suspected milk allergy. Methods: In 87 asthmatics with a suspected history and positive skin tests for milk, the 87 OFICHs and DBPCFCs were performed in combination with spirometry and followed up to 72 h after the challenge. Results: Of 87 patients, 74 (85%) developed a positive asthmatic response (AR) (20 immediate, 33 late, 6 dual late and 15 delayed; p < 0.01) and 13 (15%) developed a negative AR (p > 0.1) to OFICH. Seventy-five (86%) developed a positive AR (17 immediate, 35 late, 8 dual late and 15 delayed; p < 0.01) and 12 (14%) developed a negative AR (p > 0.05) to DBPCFC. The correlation between the OFICH and DBPCFC was statistically significant (p < 0.01). All placebo control challenges were negative (p > 0.2). Conclusions: In some adults with bronchial asthma, involvement of an allergy to cow’s milk results in the appearance of various AR types (immediate, late, dual late or delayed). The milk allergy can be confirmed by open or double-blind techniques, combined with spirometry. No significant differences were found between the OFICH and DBPCFC results. OFICH with natural milk combined with spirometry seems, therefore, to be an adequate technique for the detection of milk allergy in asthmatics. The DBPCFC can be performed as an additional check, if necessary.