Acquired Angioedema Due to C1 inhibitor Deficiency Caused by Non-Hodgkin Lymphoma in a Patient with Myasthenia Gravis

Acquired angioedema due to C1-inhibitor deficiency is a very rare disorder that usually appears in patients with lymphoproliferative and/or autoimmune diseases. This type of swelling is bradykinin mediated and does not respond to antihistamines, corticosteroids, or epinephrine. The symptoms usually appear in patients older than 40 years with recurrent episodes of angioedema without wheals. The family history is negative. The swelling could affect any tissue, but most frequently is located at the face, lips, tongue, larynx, or extremities. In the gastrointestinal tract, it causes pain, nausea, vomiting, and diarrhea. The upper respiratory airway oedema is a potentially life-threatening condition due to asphyxiation. The oedema attacks may precede the symptoms of the causative disease for months or years. In most cases, the treatment of the underlying disease resolves the angioedema episodes. Here we report a case of C1-INH-AAE caused by non-Hodgkin lymphoma in a patient diagnosed many years before with myasthenia gravis whose angioedema symptoms resolved after the specific treatment of lymphoma.