RARE GENETIC DISORDER: HEREDITARY ANGIOEDEMA TYPE 1

Abstract

SESSION TITLE: Medical Student/Resident Allergy and Airway Posters SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Hereditary Angioedema is a rare genetic disorder characterized by recurrent episodes of angioedema without pruritus or urticaria, affecting the skin or mucosal tissues of the upper respiratory and GI tract. This is caused by a mutation in the SERPING1 gene, resulting in deficiency (type I) or dysfunction (type II) of C1 inhibitor protein. CASE PRESENTATION: A 43-year-old female with PMH of recurrent episodes of angioedema requiring intubation was admitted due to chief complaint of facial angioedema, hand and feet swelling associated with dyspnea, and stridor. Due to acute respiratory failure, emergent cricothyrotomy was attempted multiple times, and eventually open tracheostomy was performed and she was placed on mechanical ventilation. Simultaneously, the patient received dexamethasone, epinephrine, and famotidine. Work up revealed low levels of C1 inhibitor and C4, consistent with bradykinin-mediated hereditary angioedema type I. Rapid weaning from mechanical ventilation to a venturi mask was achieved. Her tracheostomy tube was changed to a Montgomery long-term cannula. Later, the Montgomery tube was changed to a #6 cuffless due to hemoptysis and posterior tracheal wall irritation. Her hospital course was complicated with supraglottic edema and grade 1 subglottic stenosis treated with subglottic balloon dilation and steroid Kenalog injection. Broad-spectrum antibiotics were administered due to purulent drainage around the tracheostomy site and thick sputum concerning for tracheobronchitis. The patient had significant improvement and was successfully capped. Due to exorbitant cost and limited insurance long term prophylaxis with Takhzyro (Lanadelumab), and Icatibant was not possible. She was started on Danazol 200 mg daily with 2 rescue doses of Takhzyro SC, 6 rescue doses of icatibant 30 mg SC, and EpiPen for respiratory distress. She was counseled to avoid any NSAIDs, ACEI, tamoxifen, and was discharged to another facility for rehabilitation and decannulation. DISCUSSION: This is a case describing a rare genetic disease, with a mortality rate of 30% due to asphyxiation from laryngeal edema that accounts for less than 1% of all the angioedema episodes. Laryngeal swelling usually develops around several hours (mean of 7h). There are 3 phases: predyspnea, dyspnea, and loss of consciousness phase ending with death; with an average length of 3.7h, 41 minutes, and 9 minutes respectively. CONCLUSIONS: Early diagnosis and education are paramount in these patients, to receive long term prophylaxis as C1 inhibitor concentrate, monoclonal antibody to kallikrein (lanadelumab), attenuated androgens; avoiding exacerbating factor; and being prepared for acute attacks with the same agents. Reference #1: .https://www.haea.org/assets/img/2013Recommendations.pdf Reference #2: Uptodate hereditary angioedema DISCLOSURES: No relevant relationships by Karim Anis, source=Web Response No relevant relationships by Lady Sanchez Fernandez, source=Web Response