77 yo woman presents with significant angioedema in left side of tongue and inner cheek. Possible causes of angioedema include allergic anaphylaxis reaction, drug induced, allergic contact dermatitis, viral infection, drug induced, or a C1 inhibitor deficiency disorder acquired or hereditary. Laryngeal edema can also be caused by tonsillitis, peritonsilar abscess or pharyngeal foreign body.

                 It is unlikely that the patient has edema caused by abscess or tonsillitis since she does not have any associated fever or other signs of infection and the sudden onset of her swelling also argues against this. It is not likely a foreign body since ENT did not find anything when they scoped her.

                 It is unlikely that it is caused by a mast cell mediated etiologigy that increases vascular permeability through mast cell degranulation and release of inflammatory mediators include allergic angioedema, autoimmune mast cell release and direct mast cell release caused by medications such as opiates and radiocontrast media. It is not likely this type of reaction because these etiologies are associated with urticaria and pruritis, which the patient did not have. Also the patient did not have any exposure to a new pet, food, lotion or any other allergen or medication that could cause an allergic type reaction. The patient also does not have any history of autoimmune disease or any reaction similar to this in the past

                 It is more likely that the etiology is kinin-related where angioedema results from generation of bradykinin and complement-derived mediators that increase vascular permeability since there is no urticaria or pruritis. The most likely cause is the Altace (ACEI) that the patient has been taking caused an increase in bradykinin since it decreases angiotensin 2 which degrades bradykinin. Bradykinin can then interact with vascular receptors increasing vasodilation, vascular permeability, increased cGMP and release of nitric oxide. This reaction occurs in .1-7% of patients treated with an ACEI and it typically involves the mouth, lips, tounge, larynx, pharynx and sublottic tissues. Half of these cases usually occur within a week of starting the ACEI but can occur years later. This is a class specific reaction not a drug specific and ARBs can cause the same reaction even though these drugs don’t effect the kinin metabolism. 50% of patients with angioedema due to an ARB also had an ACEI induced angioedema (Cicardi, M, Zingale, LC, Bergamschini L, Agostoni, A. Angioedema associated with agniotensin-converting enzyme inhibitor use: outcome after switching to a different treatment. Arch Intern Med 2004; 164:910). Deficiency of C1 inhibitor can cause angioedema since levels of complement are reduced and cause increased bradykinin. This can be due to lack of C1 INH or adequate amounts of nonfunctional C1 INH. Other causes of angioedema include aspirin and NSAIDs since inhibition of cox and enzyme pathyway increases formation of pro-inflammatory leukotrienes.

                 Other possibilities in the differential of causes of swelling include cellulitis, autoimmune conditions including SLE, polymyositis, dermatomyositis and sjorgren’s syndrome. Hypothyroidism can cuase puffiness of face and lips, hyperthyroidism can cause an infiltrative dermopathy, superior vena cava syndrome and tumors can cause venous engorgement and swelling. It is not likely one of these etiologies since the patient is on an ACEI and the swelling is restricted only to her tongue and throat typical of ACEI angioedema.

Section label: Allergic Angioedema