Angioedema in the Absence of C1 Esterase Inhibitor Deficiency in a Young Patient With Anti-dsDNA Negative Lupus Nephritis

Hereditary angioedema (HAE) is an autosomal dominant condition marked by a lack of functioning C1 esterase inhibitor (C1-INH). In contrast, acquired angioedema (AAE) due to a deficiency of C1 esterase inhibitor (AAE-C1-INH) may be the manifestation of an underlying lymphoproliferative, neoplastic, or autoimmune condition. Both are potentially fatal. The C1q protein is normal in HAE but low in AAE. A third mechanism has been reported to cause angioedema, especially in systemic lupus erythematosus (SLE) patients. AAE, which happens in association with SLE, may respond well to steroids. Here we present a case of AAE in a young female with SLE that led to upper airway compromise, requiring endotracheal intubation. Early detection and treatment of such cases can lead to an outstanding prognosis by preventing airway compromise and anoxic brain injury. Even though it is a condition of either very young or middle-aged patients, practitioners must be aware of this uncommon disease linked with SLE in adolescents and young adults.