Acquired Angioedema and Chronic Lymphocytic Leukemia: Unraveling the Complex Interplay and Addressing Refractory Cases.

Acquired angioedema (AAE) due to deficiency of a C1 esterase inhibitor (C1-INH; AAE-C1-INH) is a rare and potentially fatal syndrome characterized by recurrent episodes of angioedema without urticaria. Often underdiagnosed due to its rarity and mimicry of common allergic reactions, AAE-C1-INH is associated with lymphoproliferative disorders, necessitating early recognition for improved outcomes. We present a case of a 63-year-old male diagnosed with AAE-C1-INH and concurrent stage 0 chronic lymphocytic leukemia (CLL), a rarely documented association. Despite chemotherapy, the patient experienced persistent angioedema until C1 esterase inhibitor therapy was initiated. This case underscores the importance of screening for lymphoproliferative disorders in AAE-C1-INH patients and explores refractory cases, urging further research into mechanisms and treatment strategies.