Idiopathic anaphylaxis

Question:

11/29/2017
My question is about recurrent episodes of anaphylaxis in a 20 year-old woman. She has a history of asthma, allergic rhinitis, and peanut allergy. She began having episodic urticaria and angioedema about 1 year ago. The episodes of hives and swelling became more frequent and she then began having episodes of anaphylaxis. Her symptoms include, hives, angioedema of her throat and extremities, abdominal cramping with loose stools, and chest tightness. The episodes of anaphylaxis have an onset over several hours and respond immediately to epinephrine. However, the symptoms will recur several days in a row and respond to epinephrine and antihistamines each time. Eventually the episode resolves. Her work up has been negative including serum tryptase at baseline and during an episode, alpha- gal IgE, and a bone marrow biopsy. She had three episodes of recurrent anaphylaxis that lasted for 5-7 days each in a period of about 6 months. She is on daily antihistamine (cetirizine and diphenhydramine). She was started on Xolair about 8 months ago and her urticaria and angioedema have been well-controlled. She had been without any further episodes of anaphylaxis during the past 8 months until last week when she developed the symptoms described above with her episodes of anaphylaxis for 4 consecutive days. She was treated with epinephrine, corticosteroids, and antihistamines and her symptoms resolved, but then returned the following day.

Are you aware of other similar cases and are there other management strategies that you can recommend?