Serum neutrophil chemotactic activity (NCA) during aspirin-induced urticaria and angioedema.

In order to establish the role of mast cells in aspirin-induced urticaria and angioedema, neutrophil chemotactic activity (NCA) in serum was assayed using the method of Nelson before and after aspirin challenge. In 14 (82.4%) persons sensitive to aspirin an increase in NCA during aspirin-induced urticaria and angioedema was observed and in 9 of them (52.9%) it was considerable (index NCA greater than or equal to 2.0). None of the 18 persons from the control group with idiopathic urticaria and/or angioedema but without aspirin-sensitivity exhibit an increase in NCA after aspirin challenge. The author assumes that mast cell degranulation does occur in aspirin-induced urticaria and angioedema.