DermatomyositisPolymyositisMyositisLung Diseases, InterstitialParaneoplastic SyndromesMediastinal EmphysemaIdiopathic Pulmonary FibrosisMuscle WeaknessPanniculitisHistidine-tRNA LigaseAutoantibodiesPrednisoloneLupus Erythematosus, CutaneousRheumatic DiseasesMuscle, SkeletalBiopsyImmunosuppressive AgentsMyositis, Inclusion BodyConnective Tissue DiseasesImmunoglobulins, IntravenousScoliosisTelangiectasisSkinArthritis, JuvenileMicroscopic AngioscopySeverity of Illness IndexAdrenal Cortex HormonesAutoimmune DiseasesPurpura, Thrombocytopenic, Idiopathic