Hypocomplementemic urticarial vasculitis syndrome (HUVS) and hereditary angioedema (HAE) can drive the increase of refractory angioedema, according to a study published in the Annals of Allergy, Asthma & Immunology. 

A 32-year-old man with type 1 HAE presented with angioedema and rash. He was first diagnosed with HAE at 10 years of age and was confirmed to have a genetic mutation in SERPING1. He had 2 previous episodes of laryngeal attacks that needed emergency tracheostomies. His father passed away from laryngeal edema at 29 years of age. 

The patient had been having more frequent HAE attacks requiring emergency care. He was on 150 mg of berotralstat daily as prophylaxis and icatibant for acute attacks. 

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In this latest iteration of attacks, he presented with rashes, lip and throat swelling, and abdominal pain with emesis. These symptoms commenced the night prior. He used icatibant but only a partial response was recorded. Thus, he sought emergency care. 

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A routine check found his vital signs, temperature, and blood pressure to be normal. Upon examination, there was asymmetric angioedema of the lips and hands. Rash was present at the face, chest, back, and extremities. These lesions initially appeared to be polycyclic erythematous plaques with some areas of purplish dyspigmentation. Physicians also noted symmetric-dependent edema of the lower extremities, as well as a mild case of anasarca. 

Following confirmation from laboratory studies, the patient’s physicians initiated a C1 esterase inhibitor, which only partially resolved his angioedema symptoms. Complementary medications such as H1 and H2 antihistamines and methylprednisolone likewise achieved only a partial response. 

A skin biopsy demonstrated evidence of leukocytoclasis and granulocytes within the dermal vessel walls, an observation favoring urticaria vasculitis. Additional laboratory studies confirmed this finding. The patient was started on 60 mg of prednisone daily upon discharge. Hydroxychloroquine and mycophenolate mofetil were prescribed as steroid-storing agents. 

“This case supports the previously described relationship between disorders of immune dysregulation and HAE,” the authors of the report wrote. “The clinician should be aware of other allergic/immunologic conditions that patients with HAE can have, even including other etiologies of angioedema if not responding appropriately to therapy.” 


Dorn JM, Buechler C, Nasr R, Sweet JB, Raasch J. Hypocomplementemic urticarial vasculitis syndrome and hereditary angioedema causing refractory angioedemaAnn Allergy Asthma Immunol. Published online June 16, 2023. doi:10.1016/j.anai.2023.06.014