was tun bei einer allergischen reaktion — what are common causes?

For an allergic reaction, first recognize symptoms: rash, itching, swelling, breathing difficulty, or circulatory collapse. Common triggers include pollen, pet dander, dust mites, mold, insect venom, foods (e.g., nuts, milk, eggs, shellfish), and drugs (e.g., penicillin). For mild reactions, antihistamines (e.g., cetirizine) and topical corticosteroids help. For severe anaphylaxis, call emergency services immediately; epinephrine auto-injectors (e.g., EpiPen) are life-saving. Allergy testing (skin prick test or blood IgE test) can identify specific triggers. DNA tests for allergies are not well-validated – they indicate genetic predispositions, not active allergies. Evidence for such genetic tests is weak (mechanistic, not diagnostic). If you suspect an allergy, consult a doctor or allergist. Avoidance of known triggers and having an emergency plan are key. Evidence is based on clinical practice and guidelines (e.g., EAACI, AWMF).