Design: A quality-control retrospective review of medical records was conducted for cases of anaphylaxis encountered at Mayo Clinic Rochester during a 3 1/2-year period.
Patients: For inclusion in the study, all patients had to manifest general symptoms of mediator release such as generalized pruritus, urticaria, angioedema, and flushing. Of the 179 patients with anaphylaxis (mean age, 36 years), 66% were female, 49% had atopy, and 37% had a previous history of immediate reactions to allergens. Of these study patients, 11 were receiving medications capable of exacerbating anaphylaxis (beta-blockers in 7 of them).
Results: Consultation with an allergist was obtained in 142 cases, and a probable diagnosis was made after review of the medical records. Causes of anaphylaxis included foods in 59 patients, idiopathic in 34, Hymenoptera in 25, medications in 23, and exercise in 12; false-positive diagnoses were recorded in 18. Allergy prick tests were done in 104 patients, 71 of whom had positive results; allergen-specific IgE tests were done in 44 patients, 23 of whom had positive results. In 19 patients, only allergen-specific IgE testing was done, and results were positive in 12. Normal test results included C1 esterase inhibitor in 33 patients, metabisulfite challenge in 15, and dye or preservative challenge in 10. Food skin tests were graded on a relative value scale and revealed 15 highly allergic, 24 moderately allergic, and 39 weakly allergic food groups.
Conclusion: A standard protocol should be used for assessment of patients with anaphylaxis, and fresh food extracts should be used for prick skin testing. A national incidence study of anaphylaxis is needed. The public and school personnel should be educated about food anaphylaxis, and emergency treatment for anaphylaxis should be readily available for patients.