wie lange kein cetirizin vor allergietest — what are common causes?

Before an allergy test (skin prick or intradermal), cetirizine should be stopped for 3–7 days depending on medical advice, as it blocks histamine release and can cause false-negative results. The exact duration depends on the drug's half-life (approx. 8–10 hours) and individual sensitivity; many guidelines recommend at least 5 days. Common allergy triggers include pollen (grasses, birch, ragweed), dust mites, pet dander, mold, and insect venom. Food allergies (peanuts, milk, eggs) and medications are also frequent causes. Important: Do not discontinue antihistamines without consulting your doctor, especially if you have severe allergies or asthma. An allergy test without proper washout may be unreliable and lead to misdiagnosis. Evidence is based on clinical practice and guidelines from allergy societies (e.g., EAACI).