Methods: Case report and literature review.
Results: A healthy 41-year-old female patient related a sudden reaction of cough, eye tearing, edema in the right hemiface and some discomfort in throat. She was then medicated with oral antihistamine and corticosteroids, with gradual improvement of the symptoms. One week after the reaction, she had no remaining symptoms, and was examined by an allergist, referring no previous history of respiratory allergy. She just mentioned that the reaction started five to ten minutes after eating an omelet with ham and cheese that she prepared. She denied any medication in the past 30 days. With no history of food allergies or drug reactions, the initial diagnosis was spontaneous or idiopathic immediate hypersensitivity reaction. Immediate skin prick tests were performed for food and airborne allergens, which were positive for eggwhite and egg yolk. Tests for milk and common airborne allergens were all negative. Then she performed in vitro specific IgE tests, which results were: eggwhite: 1,51 kU/L; egg yolk: 0,52 kU/L; ovalbumin: 1,04 kU/L; ovomucoid: 0,0 kU/L. The Patient declined to go Double-blind-placebo-controlled food challenge.
Conclusions: This patient had no previous history of food allergy, including eggs. She usually cooked and ate omelets and other foods containing eggs without symptoms. This case probably reflects a de novo sensitization to a previously tolerated food. We assume that the reaction resulted from ingestion of incompletely baked egg. With this diagnosis, the patient was warned to avoid raw egg, but encouraged to continue eating extensively-baked or cooked foods containing eggs, which she did with no further reaction. She was advised to take H1N1 influenza shot, without adverse reaction. This case emphasizes the importance of the clinical history and points for attention to unusual or less common allergen sources in adulthood.