AB1031 ETANERCEPT-INDUCED LUPUS-LIKE SYNDROME IN THE BOY WITH IDIOPATHIC DERMATOMYOSITIS OR DELAYED MANIFESTATION OF SYSTEMIC LUPUS ERYTHEMATOSUS?

Background Treatment of juvenile onset rheumatic diseases (RD) is an ongoing problem because of the more aggressive disease course and more various clinical manifestations than adult-onset RD. Since the main clinical symptoms may overlap between well-known various RD, in some cases the path to diagnosis and the search for optimal therapy takes longer, especially in patients of pre-adolescence and adolescence. Objectives We described a rare case of one boy with RD who presented initially with severe dermatomyositis with sequential evolution to systemic lupus erythematosus. Methods Case report. Results A 8 yo male patient with normal physical, psychosocial and cognitive development experienced muscle weakness, periorbital erythema, Gottron symptom, dysphagia in September 2015 y, which developed after insolation. When he was admitted to hospital, increased levels of muscle-derived enzymes and positivity of ANA 1:640 were found. He was diagnosed as having juvenile dermatomyositis and was treated with prednisolone (Pr) for 3 years (IV courses repeated and per os constantly, max dose 1.5 mg/kg/day, min dose 0.5 mg/g/day), IVIG courses repeated and sequentially methotrexate, hydroxychloroquine, cyclosporine with short time of remission. Muscle weakness disappeared after the treatment, but in October 2015 y he experienced new eruptions on his face, heavy aphtosis stomatitis, lymphadenopathy, distal polyneuropathy, weight loss without strong effect after increase the dose of Pr, IVIG courses repeated, cyclosporine and added of abatacept during 6 months. Because the response to this treatment was low, etanercept was started in June 2016 y, but after two injections he had flare of disease: bright rash on the face, scalp and legs, hard aphthosis stomatitis, cheilitis, cognitive disorders, diffuse alopecia. He received IV course of Pr without significant stable effect. We reviewed diagnosis as systemic lupus erythematosus and changed therapy in November of 2016. Because he had steroid’s osteoporosis with spondylopathy, this combination that made us initiate treatment with mycophenolate mofetil and repeating courses of rituximab (3 courses in total) without increased dose of Pr. Clinical features gradually improved and now he feel goog and receive mycophenolate mofetil and Pr 5 mg/day. Conclusion This clinical observation can be considered as a course of overlap-syndrome with a successive phase change that could be triggered by anti-TNF therapy, or as an unusual course of SLE in a male patient with a predominance of myositis at onset. Treatment strategy, including of Pr, mycophenolate mofetil and rituximab in a young patient proved successful for treatment and seems to be justified in similar cases. Disclosure of Interests None declared