MDA5 Juvenile Dermatomyositis Misdiagnosed as Childhood Psoriasis: A Case Report

Abstract

Juvenile Dermatomyositis (JDM) is a rare autoimmune disorder which mainly affects the skin and skeletal muscles. Characteristic features of this rare disorder include Gottron papules, heliotrope rashes and proximal muscle weakness. MDA5 positive JDM is usually associated with interstitial lung disease in later part of life. The authors report a case of an 11-year-old male child who presented to the Paediatric Department with complaints of rashes over extensor surfaces, Gottron papules and pain and weakness in all limbs. The child was on treatment from the Dermatology Department as a case of psoriasis for last six months. During hospital stay after detailed work-up, the child was diagnosed to have JDM. Anti-melanoma Differentiation-Associated gene 5 (Anti-MDA5) antibodies were positive in the present case. The child was treated with immunosuppressive drugs with supportive care and is currently on treatment for the last one and a half years and is largely asymptomatic. JDM requires meticulous clinical examination and specific investigations so that timely diagnosis can be made to ensure appropriate treatment. In the present index case, the authors describe the typical clinical presentation, newer investigative modalities like myositis specific antibody and treatment outcomes of this rare condition.

Keywords

• gottron papule
• inflammatory myositis
• melanoma differentiation-associated gene 5 antibody