Acquired Angioedema: A Case of an Unexpected Death and Review of the Literature

Abstract

Angioedema is a rapid swelling of the deep layers of skin including dermis, subcutaneous tissue, mucosa, and submucosa. It results from rapid release of inflammatory mediators that increase the permeability of capillaries and venules through mechanisms involving mast cells or bradykinin. It can be classified as allergic, drug-induced, hereditary, acquired, and idiopathic. Acquired angioedema occurs when the C1 esterase inhibitor, which plays a role in down-regulating the complement system, is absent or defective. Diagnosis of this disorder should be considered in any patient presenting with episodes of swelling affecting cutaneous tissues and mucous membranes in or beyond the fourth decade of life, without a family history of angioedema. While the disorder can occur in isolation, the majority of patients have an underlying lymphoproliferative disorder or other malignancy. The clinical course of acquired angioedema is often unpredictable and attacks can range from minor swelling to unexpected death. The following case report describes a fatality due to acquired angioedema in a man with an underlying monoclonal gammopathy of undetermined significance. A thorough review of the medical and family history, antemortem laboratory values, autopsy examination, and postmortem serum tryptase levels were all used to make the diagnosis and rule out other forms of angioedema. This case is presented, along with a review of other causes of death involving angioedema, in order to aid forensic pathologists in working up and certifying these deaths.