was tun bei allergischer reaktion — what symptoms are typical?

Typical symptoms of an allergic reaction range from mild (sneezing, itching, hives, runny nose, watery eyes) to severe (shortness of breath, swelling of lips/tongue/throat, drop in blood pressure, anaphylaxis). For mild symptoms, antihistamines (e.g., cetirizine) and topical corticosteroids help; for breathing difficulties or circulatory collapse, call emergency services immediately and use an epinephrine auto-injector if available. Allergen identification via skin prick testing or specific IgE is recommended. The provided context lacks allergy-specific data; this answer reflects standard medical practice. Evidence level: practice guidelines.