wie lange vor allergietest keine antihistaminika — can a DNA test help?

The question of how long to stop antihistamines before an allergy test (e.g., skin prick test) is purely clinical and depends on the specific drug. Typically, systemic antihistamines are discontinued 3–7 days prior, while topical or short-acting agents may require shorter intervals. The provided knowledge base contains no studies or guidelines on this topic. A DNA test cannot answer this question. It might theoretically identify genetic variants in histamine metabolism (e.g., DAO, HNMT) that influence individual histamine tolerance, but that does not replace a concrete washout period. The evidence for such genetic tests is weak (mechanistic, small effect sizes), and the clinical decision remains with the physician. Safety note: Stopping antihistamines without medical advice can cause severe allergy symptoms; always consult your allergist.