Hypersensitivity to Acetylsalicylic Acid or Aspirin (and other NSAIDS) is a condition that affects up to 2,5% of the population. Most cases are seen in a complex of such hypersensitivity with chronic eosinophilic rhinosinusitis with nasal polyposis and asthma. Despite research in finding a reliable in-vitro-test for the condition, challenge tests are still considered gold standard. So far oral, nasal, inhalation and intravenous routes of administration has been described in literature.