Angioedema of neck

Findings

CT of the neck one month prior revealed asymmetric thickening of the pharyngeal mucosal space and the submucosal larynx on the left. Current CT of the neck shows asymmetric, mass like soft tissue in the right parapharyngeal space and associated structures with resolution of findings on the L side.

Differential diagnosis:
- Angioedema
- Peritonsillar edema/abscess
- Pharyngeal carcinoma
- Lymphoma
- Facial lymphedema

Additional clinical history: Patient is on Angiotensin converting enzyme (ACE) inhibitor therapy.


Diagnosis: Angioedema of neck


Key points

Angioedema is localized subdermal or mucosal swelling due to postcapillary venule inflammation.
Angioedema is mediated by vasoactive substances (like histamine) which locally dilates vessels and causes local vascular leaking.
Angioedema is classified as hereditary, acquired, allergic, secondary to medication or idiopathic.
Examples of medications causing angioedema are radiocontrast agents, ACE inhibitors, Aspirin and NSAIDs amongst other agents.
Angioedema can occur anywhere in the body but often involves the head and neck, including face, lips, tongue, and larynx and the GI tract.
Angioedema can cause acute airway compromise and death.
Radiologist may encounter angioedema when imaging the head and neck or the small bowel, or may encounter it related to contrast reactions.
ACE inhibitors cause angioedema in 0.1-0.5% of patients who use them, and is reported to be the leading cause of acute angioedema in the emergency department with 20% of cases being life-threatening.
Radiographic findings in the head and neck include swelling of the epiglottis, aryepiglottic folds, and prevertebral and submental soft tissue.
Angioedema is a cause of unexplained acute or chronic abdominal pain.
Abdominal CT findings included thickening of small bowel wall and mucosal enhancement.