RECURRENT ANGIOEDEMA AS A PRESENTING SYMPTOM OF MIXED CONNECTIVE TISSUE DISEASE IN A PEDIATRIC PATIENT

Abstract

Introduction Idiopathic angioedema without urticaria presents infrequently and warrants investigation for an underlying etiology. Autoimmune conditions are a rare cause of acquired angioedema (AAE). The identification of an underlying cause has significant potential implications for treatment and thus resolution of AAE. We present a patient who was diagnosed with mixed connective tissue disease (MCTD) after initially presenting with recurrent angioedema. Case Description A 17-year-old female with a six-month history of recurrent angioedema without urticaria presented for evaluation to an outpatient pediatric allergy clinic. At initial presentation, she denied musculoskeletal complaints. Laboratory evaluation revealed a significantly elevated sedimentation rate with a normal C-reactive protein. Over the next several months she developed pain and stiffness, particularly in her wrist and elbow joints. These findings triggered rheumatologic referral for further evaluation. She was ultimately diagnosed with MCTD with corresponding U1-ribonucleoprotein antibodies and high titer anti-nuclear antibodies. She was started on mycophenolate mofetil and hydroxychloroquine for MCTD treatment with resolution of her arthritis and no further episodes of angioedema. Discussion The pathophysiology of nonhistaminergic idiopathic angioedema remains unknown. This case highlights the need to asses for concurrent rheumatologic and autoimmune symptoms while evaluating AAE in the absence of urticaria, especially in the pediatric population. To our knowledge, this is the first report of MCTD presenting as acquired angioedema in published literature.