A Case of α-Gal-Unrelated Red Meat-Induced Urticaria Treated by Omalizumab

A 70-year-old healthy woman was referred to our hospital for chronic urticaria. She did not have a history of allergy, asthma, and rhinitis. She was initially diagnosed with α-gal-related urticaria based on an episode of delayed-type urticaria after eating red meat. The results of the intracutaneous allergen test for beef and pork were negative. Fluorenzyme immunoassays specific for IgE against α-gal, beef, and pork were also negative. She was diagnosed with an α-gal-unrelated red meat allergy following the reproduction of urticaria by a food challenge test. The patient was unresponsive to several drugs, including antihistamines or immunosuppressants. However, omalizumab administration suppressed her symptoms. <b><i>Key Clinical Message:</i></b> The diagnosis of red meat allergy may require a repeatability test by consuming red meat even though serum α-gal IgE antibody might be negative. The α-gal-unrelated red meat urticaria may be responsive to omalizumab.

Improving Successful Introduction after a Negative Food Challenge Test: How to Achieve the Best Result?

Oral food challenges (OFC) confirm or exclude the presence of a food allergy. The outcome can be positive (allergic symptoms), inconclusive, or negative (no symptoms). In the case of a negative OFC, parents and children are advised to introduce the challenged food allergen into their diet. However, previous studies showed difficulties in a successful introduction at home. The aim of this prospective non-randomized intervention study is to evaluate the effect of a new strategy with more guidance regarding the dietary introduction after a negative food challenge test. We compared two cohorts: an historical (retrospective) control group of 157 children, previously described, who did not receive any special advice after a negative OFC, versus a new cohort consisting of 104 children, who were guided according to our new strategy of written introduction schemes, food diaries, and several phone calls. In the historical control group, introduction was successful in 56%, partially successful in 16%, and 28% failed to introduce at home. After introduction of our new strategy, complete introduction was found in 82%, 11% had partially introduced, and only 8% failed to introduce the allergen. In conclusion, comprehensive advice and dietary recommendation after a negative OFC results in an increase in successful home introduction. Therefore, more attention, guidance, and follow-up of children and parents are desirable after a negative OFC.