B63-09 A Child With Refractory Juvenile Dermatomyositis Requiring Pap Therapy

Abstract Introduction Juvenile dermatomyositis (JDM) is the most common inflammatory myopathy in children, but it is rare, with an estimated annual incidence of 2–4 in 1 million children in the United States (1). Several studies have addressed the occurrence of respiratory complications in dermatomyositis and polymyositis, revealing hypercapnic respiratory secondary to muscle weakness, and obstructive sleep apnea (2). Selva-O’Callaghan et al found that the frequency of obstructive sleep apnea in adult patients with inflammatory myopathy is high, with a mean AHI 28.7/hour (3). In this case report, we present a 7-year-old child who had a refractory juvenile dermatomyositis with severe muscular and oropharyngeal weakness and diagnosed with obstructive sleep apnea requiring PAP therapy. Case presentation A 7-year-old female newly diagnosed with JDM (+anti-MJ /NPX-2 antibody) was admitted for IV methylprednisolone, IVIG, and SC methotrexate therapy given proximal weakness and heliotrope rash. She was discharged on home therapy without a pulmonary evaluation due to rapid improvement. She was readmitted 2 weeks later in acute respiratory distress requiring Bi-PAP support with severe progression of oropharyngeal and proximal weakness. Rituximab, hydroxychloroquine and cyclophosphamide were added to her regimen. The respiratory negative inspiratory force (NIF) improved after 1 month ( - 34 cm H20) and she was weaned off Bi-PAP. Her first PFT showed severe restriction (FVC 34%, FEV1 36%). Polysomnography demonstrated moderate obstructive sleep apnea (OAHI of 8.3/hr, SpO2 nadir 84%, mean O2 95%, CO2 level 40 mmHg). Based on this study, she was discharged on nocturnal CPAP at 6 cm H20. After fourth months of follow up, her CPAP was discontinued due to normalization of her PFT’s (FVC 94%, FEV1 89%, Peak cough 220 L/min, MIP/MEP -75/65 cm H20) and polysomnography (OAHI 1.9/hr, SpO2 nadir 90%, mean O2 98% and CO2 level 40 mmHg). Discussion and conclusion Involvement of upper airway muscles, diaphragms, and other respiratory muscles in dermatomyositis can respectively cause obstructive sleep apnea and ventilatory failure, which may require intensive immunosuppressive therapy and noninvasive ventilatory support (4). Albrecht K et al have reported that the general prevalence of sleeping disorders in idiopathic inflammatory myopathies is around 51% (5). George et al found that patients with DM have abnormal PFTs (at least 10% decline in FVC) (6). This case highlights the importance of monitoring respiratory function with PFTs and to consider inpatient Polysomnography to determine the level of respiratory support and evaluate response to immunotherapy. This abstract is funded by: None