Oral Food Challenges
A total of 17 OFCs were performed, of which 15 were conducted to diagnose secondary nut allergy, with non-culprit nuts, and 2 to clarify index reactions to a specific nut. Of the first 15 OFCs, 9 were performed to other nut to which patients were sensitized, but not exposed to before, all of them with negative or low levels of sIgE (<2 kU/L) to the respective nut. In the remaining 6 OFCs, patients had negative skin tests/sIgE and an OFC was performed to confirm non-allergy and safety in nut introduction. Six (35%) OFCs were positive (4 with non-culprit nuts and 2 with the suspected nut). All these patients had mild cutaneous reactions (2 pruritus, without lesions, and 4 urticaria), 4 of them with spontaneous resolution. The remaining 2 had symptoms resolution after treatment with oral antihistamines.