LAUSR

Inflammatory myopathies (IMs) are a heterogeneous group of muscle diseases, which are rarely diagnosed during childhood (1). Paediatric patients usually require a wide spectrum of diagnostic tools, especially if atypical features are displayed. We report a 12-year-old female who presented with suspected myositis, with an acute onset of proximal muscle weakness without any cutaneous involvement. Her history was unremarkable, except for congenital hip dysplasia. Laboratory tests showed high creatine kinase (CK; 1590 U/L) and negative inflammatory markers and autoantibodies. Electromyography of the quadriceps revealed muscular damage and total-body short tau inversion recovery (STIR) magnetic resonance imaging (MRI) showed diffuse muscle hyperintensity (Figure 1A). Biopsy of the vastus lateralis showed inflammatory infiltration with perifascicular atrophy (Figure 1C, D). High-dose steroids and weekly