Box 1.

Delayed, or Late Night, Anaphylaxis to Red Meat: the presentation and the clinical problem

I. For several years prior to 2008, patients were presenting to general medicine or allergy clinics for investigation of anaphylaxis or recurrent episodes of urticaria where the cause was not obvious

II. The histories were striking for i) onset as an adult, ii) presentation late at night and/or iii) no apparent acute cause; i.e., no bites or stings; no medicines and no foods within 3 hours of the episode

III. The majority of cases had no history of conventional symptoms of food allergy; however, a significant proportion of the cases had made an association with eating beef, pork or lamb earlier in the day

IV. When the subjects were tested using a prick test with commercial food extract, including beef, pork or lamb, they were found to have negative or very small responses (i.e., 2-3mm wheals) to the meats

V. Because of the adult onset, long interval after eating, and “negative” prick skin tests, many or most of the patient were told they did not have food allergy; nonetheless, they had specific IgE for alpha-gal as well as beef, pork and lamb