[Acetylsalicylic acid pseudoallergy: an anomaly of thrombocyte function?]

After a short historical review, the clinical symptomatology of the pseudoallergic reactions (PAR) after intake of acetylsalicylic acid (ASS) is examined. An intolerance to ASS mostly becomes manifest as bronchial asthma--sometimes up to a status asthmaticus: it is frequently combined with vasomotoric rhinopathia and nasal polyps (so-called "aspirin triad") or as urticaria and angio-edema, seldom as a shock reaction. These symptoms can - in contrast to an allergy--appear at the first intake of the drug. Changes in the arachidonic acid metabolism are of pathogenetic importance, as all substances that inhibit the cyclooxygenase pathway [e.g., most of the nonsteroidal anti-inflammatory drugs (NSAIDs)] are not tolerated by ASS-sensitive patients. Generally, a typical clinical history is sufficient for the diagnosis. Due to the fact that the ASS and NSAID pseudoallergy so far cannot be proved by in vitro methods, oral or inhalative provocation tests are needed when the tolerance situation to the drugs is unknown. However, these tests present high risks. A research group working with Capron (Lille) has recently been able to prove that washed platelets from patients with an analgetic asthma syndrome show an abnormal in vitro response to ASS or NSAID - like indomethacin and fluriprufen - which is characterized by liberation of cytocydal supernatants against parasites, as well as of free O2 radicals, which can be detected by chemiluminescence. Therefore, a platelet anomaly of arachidonic acid metabolism seems to be pathognomonic for ASS asthma. It is not yet known whether or not this is also related to ASS urticaria.(ABSTRACT TRUNCATED AT 250 WORDS)