Hereditary angioedema: imaging manifestations and clinical management

Abstract

Hereditary angioedema is a genetic disorder typically related to insufficient or dysfunctional C1-esterase inhibitor. Patients present with episodic swelling of various body parts, such as the face, neck, bowel, genitals, and extremities. Acute or severe symptoms can lead to patients presenting to the emergency room, particularly when the neck and abdominopelvic regions are affected, which is often accompanied by radiologic imaging evaluation. Patients with hereditary angioedema can pose a diagnostic challenge for emergency department physicians and radiologists at initial presentation, and the correct diagnosis may be missed or delayed, due to lack of clinical awareness of the disease or lack of its consideration in the radiologic differential diagnosis. Timely diagnosis of hereditary angioedema and rapid initiation of appropriate therapy can avoid potentially life-threatening complications. This article focuses on the spectrum of common and characteristic acute imaging manifestations of hereditary angioedema and provides an update on important recent developments in its clinical management and treatment.

Hereditary angioedema in children and adolescents – A consensus update on therapeutic strategies for German‐speaking countries

“…Particularly, abdominal attacks are sometimes accompanied by vomiting and diarrhea, both frequent symptoms in childhood. In cases of recurrent, unclear abdominal pain, we therefore strongly recommend sonography during an acute phase, whereby a thickening of the bowel wall in particular is a sign of HAE‐C1‐INH 12 . However, mild intestinal edema may be overlooked on imaging even in symptomatic patients 13 so that negative scans do not necessarily exclude a diagnosis of HAE‐C1‐INH.…”

Diagnosis and screening of patients with hereditary angioedema in primary care

“…Imaging tests are generally not a useful diagnostic tool and are only helpful if taken during an acute episode; taken too early or too late, these tests will return false-negative results. 63 Subtle or mild intestinal edema may be overlooked on imaging even in symptomatic patients. 64 As a result, negative scans do not necessarily exclude a diagnosis of HAE.…”

“…Radiographs and conventional barium studies may demonstrate thumb printing due to bowel wall thickening in HAE, and bowel lumen narrowing or bowel distention can be present, although these scans may also display results nonspecific to angioedema. 52 , 63 , 64 The jejunum and duodenum are the most frequently affected bowel segments during an acute episode, with the colon, ileum, and stomach involved much less frequently. 63 Contrast-enhanced CT scan may help exclude other causes of abdominal pain.…”

“… 52 , 63 , 64 The jejunum and duodenum are the most frequently affected bowel segments during an acute episode, with the colon, ileum, and stomach involved much less frequently. 63 Contrast-enhanced CT scan may help exclude other causes of abdominal pain. 63 – 65 Ultrasound may be used instead in pediatric patients to exclude other etiologies.…”

“… 63 Contrast-enhanced CT scan may help exclude other causes of abdominal pain. 63 – 65 Ultrasound may be used instead in pediatric patients to exclude other etiologies. 63 Endoscopic procedures in HAE episodes have not been well described, and are generally discouraged since local trauma may induce a potentially life-threatening episode of laryngeal angioedema.…”