Anaphylaxis, part 1: Clues to recognition

Common causes of anaphylaxis in adults are foods, medications, and insect stings, although some reactions have no identifiable cause. Initial symptoms often involve the skin and may include pruritus, erythema, and a feeling of warmth and flushing. The most common sign is urticaria with or without angioedema. Dyspnea, wheeze, dizziness, nausea, upper airway edema, and hypotension also may occur. The diagnosis is made based on the history, physical findings and, occasionally, laboratory data. Asking patients about the time of day of the occurrence and its relationship to exercise, meals, and medications can help identify the cause. Questions on whether their medications have changed recently and what food items were eaten before the episode can be particularly helpful. Tests to determine specific IgE and antibiotic skin testing may be useful in some patients.