594 Life-Threatening Angioedema without Urticaria (Ae-U)

BACKGROUND: This paper addresses diagnosis and treatment of life- threatening angioedema without urticaria (AE-U) with emphasis on newer concepts on patient safety and updated knowledge about pathophysiology. AE-U may be idiopathic, hereditary or acquired secondary to adverse “allergic” reactions to aspirin (ASA), angiotensin-converting enzyme inhibitors (ACEIs), angiotensin-receptor blockers (ARBs), non-steroidal anti-inflammatory drugs (NSAIDs), or other drugs. Serious adverse reactions to these drugs are becoming more common as they are increasingly prescribed for hypertension and other cardiac disorders. METHODS: We used electronic databases to gather information on angioedema. We also documented and analyzed a case of drug-induced acquired angioedema from ACEI resulting in repeated intubations and prolonged ICU stays. RESULTS: Case report—A 69 year old female presented with rapidly progressive swelling of the tongue. She was intubated and underwent cricothyrotomy. She had been admitted in 2003 and 2005 for angioedema; in 2003 she was instructed to avoid OTC cold medications, ACEIs, and NSAIDS, and in 2005 told she had an allergy to ACEI, ARBs, ASA, and NSAIDs. Although this was noted in her charts, the PMHx and allergy list were incorrect or inconsistent throughout her subsequent admissions and office visits from 2005 to 2008. This data suggests 3 serious concerns for patient safety: (1) documentation of “drug allergy,” (2) ED diagnosis and treatment of angioedema, (3) follow-up from ED to outpatient care for angioedema. Once initiated, serious upper airway obstruction may take seconds to days to progress. After starting the drug, it may take days to years before a serious episode occurs, highlighting the significance of proper documentation in medical records. ED diagnosis may be difficult but should differentiate between angioedema with and without urticaria as the latter does not respond well to IV antihistamines, commonly given as first-line treatment in the ED. Newer treatment options for angioedema may include C1-INH concentrate, ecallantide, and icatibant. Outpatient follow-up should include workup for HAE, AAE, and angioedema with urticaria (AE+U) by a specialist. A proposed algorithm for AE-U is presented. CONCLUSIONS: Severe AE-U may be difficult to diagnose and treat in the ED—patient safety may be improved with documentation, newer treatments, and outpatient follow-up.