welche allergien gibt es — what symptoms are typical?

Allergies are hypersensitivity reactions of the immune system to normally harmless substances (allergens). Typical symptoms vary by allergen and affected organ system: respiratory (sneezing, runny nose, coughing, shortness of breath from pollen or dust mites), skin (itching, redness, hives, eczema from contact allergies or atopic dermatitis), gastrointestinal (nausea, diarrhea, abdominal pain from food allergies), and systemic (anaphylaxis with circulatory collapse). Common allergies include pollen, dust mites, animal dander, mold, insect venom, foods (e.g., peanuts, milk, egg), and medications. Importantly, many commercial tests, such as IgG blood panels for food intolerances, are not scientifically validated. IgG antibodies indicate exposure, not intolerance. Similarly, genetic tests for lactose intolerance or gluten sensitivity cannot replace clinical diagnosis (breath test, biopsy). The evidence for such consumer tests is weak to misleading. If an allergy is suspected, consult a physician or allergist for proper diagnosis through history, skin tests, and specific IgE testing.