Allergi - #10565

Hello, I would like to ask for medical advice regarding possible allergy/anaphylaxis. I am a 46-year-old woman living in Switzerland. I had two reactions after eating walnuts. Both times it started with itching/scratching in my throat, then coughing and a feeling of tightness in my chest and breathing. I went to the hospital both times and received adrenaline (epinephrine), the first time after about 1 hour and the second time after around 30–40 minutes. However, allergy tests (blood tests) did not show a clear allergy. Doctors mentioned something like “idiopathic anaphylaxis.” I never had skin symptoms like hives (urticaria) in my life. About one year later, I ate pistachios and felt slight throat irritation, but I believe this was anxiety/panic with hyperventilation, not a real allergic reaction, because symptoms were different and did not progress. My questions are: • Is this likely a true walnut allergy even if tests are negative? • Do I need to carry an epinephrine auto-injector at all times? • Should I avoid all nuts or only walnuts? • Could this be something like mast cell activation or is that unlikely? Thank you very much for your help.