I have a son who is sixteen years old and has a pacemaker ever since he was born. He suffers from a three degree heart block while I suffer from lupus. It was in November 2008, that he was replaced with a new lead and generator. His doctor always prescribes aspirin for him after each operation of lead change to reduce the risk of blood getting clotted. But he had to be admitted to the ER from school just before thanks giving due to severe breathing difficulties. The doctors found some difficulty in getting an IV started. They feel that my son had gone through a blood clot, but when they made him undergo a CT scan, they were unable to find it. His usual doctor who then came commented that it could have been Aspirin that caused the asthma attack but I am not really sure about it as he has undergone this treatment several times. I would like to know what kind of test should be done to find out whether my son has an allergy to aspirin. If someone could shed some light on this matter, I would be very grateful. So please do get in touch with me at the earliest if you can help me out.