1. Polymyositis a rare entity in childrenDr Aisha Qaisar (Senior Registrar).Children Hospital Lahore.Dr Zahid Jamil ( Registrar). ChildrenHospital Lahore

2. 10 Year old Boy presented with Muscles weakness, Dysphagia and Tip toe walk 3. History Name Usman Age10 Year Resident Okara DOA17-10-12 MOAOPD 4. Presenting Complain weakness25days Walk on tip of toe07 Days Dysphagia 02 days Speech Nasal in quality 01 day 5. HOPCProgressive weakness difficulty in performing every day work. Getting up from bed Climbing stairs Unable to change his cloth Difficulty in keeping his head up (Head drop)He had difficulty in walking(Unsteady). Tip toe walk 7 daysAfter admission during stay in ward dysphagia. Initially to liquid than s0lidNasal twang voice 6. Cont.No history of; Cutaneous lesion , o Rash over face , hands neck or shoulder. Heat or cold intolerance constipation ,diarrhea. Photosensitivity, oral ulcer, hair loss. Rhaynauds phenomenon Any drug intake 7. Cont He is developmentally normal child Grade 4 doinggood at educationConsanguineous marriage twin brother. No family h/o myopathy Vaccinated no h/o TB contact Poor socioeconomic class 8. Examination General physical examination Conscious ,Oriented, cooperative, but miserable look andlying in agony in bed. Ht 150cm. Wt 30 kg. Temp 98F. BP 180/80. Generalized edema and muscle tenderness. No rash over body. No joint inflammation, deformity. No calf muscle hypertrophy No skin tightening or telangectasia 9. Central Nervous system Gcs 15/15 Tone normal Power 3/5 in both upper and lower Proximal muscle weaknesslimb at hip and shoulder joint finemovements of hand were intact Reflexes were elicit able Sensation was intact cranial nervealso intact No ocular facial or respiratorymuscle weakness were noted attime of admission. Gower sign +ve He was walking on tip of his toes. GIT..normal CVS..normal Respiration normal 10. D/D Based on these finding following diagnosis we initially considered.A. Acute Viral myositisB. PolymyositisC. dermyomyositis 11. Proximal muscle weakness in the absence of cutaneous lesion is suggestive of Polymyositis. 12. Investigation CBC ESR..45 Hb10CRP10 TLC..11OOO N.63% L21% CPK.2036 Plt543LDH............1613ANA -VERAF -VE ECG NormalNCS Normal CXR Normal 13. EMG 14. Muscle biopsy 15. Inflammatory myopathy Group of disordercharacterized by; Proximal muscle weakness Non suppurativeinflammation of skeletalmuscle with predominantlylymphocytic infiltrate 16. Inflammatory myopathy Clinical Classification Dermatomyositis Polymyositis Inclusion Body myositis 17. Epidemiology Rare disease in children Usualy seen after 18 yrs Incidence in USA is .5 to8.4/million population. More common in female 18. Cause Autoimmunein origin 19. T cell mediated Asso: othermyocytotoxity autoimmune dis:ComlimentAuto antibodiesmediatedmicroangiopathyResponse toHistocompatibility genesimmunosuppressive therpySupported by 20. T cell mediated cytotoxictyViralMalignanciesC.T Disorders 21. Pathophysiology Cytotoxic Cd8+T Invade muscle tissue Damaging Vescular endotheliumVirus Muscle destruction CKAbnormal expression MCHC 22. Auto antibodiesdectected in 60-80% Types: Myositis associated Ab Myositis Specific Antibody 23. Myositis associated Autoantibodies: Shared with otherautoimmune dis: Found in 20-50% ofPatients 24. Myositis Specific antibodies Unique to myositis. Found in 40% of cases. Three main types:Anti -jo -1 Ab Anti - Mi-2Anti-SRP 25. ILD Arthritis Acute onset Fever Good Prognosis Good Response to Therpy.Cardiac InvolvewmentPoorPrognosisPoor response to therapy 26. Ocular And Facial Musclesnever InvolvedDysphagia and dysphonia may occurNeck muscles are involved in50 %of casesShoulder and Pelvic muscles Mostseverly affectedDistal muscles are sparedIn majority and early in the course Usually insidious in onset Toe walking No identified precipitant Skin Rash always absent 27. Arthritisarthlalgia Dysphagia Nasal regurgitation Reflux oesophagitisSLESarcoidosisSjogren Abdominal Bloating Odynophagia Constipation 28. MyocarditisTachyarrythmias Interstitial PneumonitisArioventconductiondefectInterstitial fibrosis 29. Dignosis. Muscles enzymes EMG Muscles biobsy Antibodies dectection Imiging studies Complete bld count 30. CK inc; up to 50 times ALT AST AldolaseLDH 31. Imaging studies MRI USG To Localize theextent of muscleinvolvement. 32. CBC Leucocytosis or thrombocytosis >50%ESR increasedCRP Increase in >50% 33. Shared features Both Inflamatory Myopathies Distinct Develop over FeaturesWks to months. Response to Steriod Demographic Dermatomyositis Features. vs Peculiar Dematological Polymyosits finding. Muscle biopsyfeatures. Calcinosis 34. ACR Ctitaria for PM/DM(Bohan & Peter (1975) NEJM) Diagnostic Critaria.1. Proximal muscle weakness2. Elevated serum CK3. Myopathic changes on EMG4. Muscle biopsy demonstrating Lymphocytic infiltration5. Typical skin rash of Dermatomyositis eg Gottron, Shawl,Helitrop 35. ACR Ctitaria for PM/DM(Bohan & Peter (1975) NEJM) Using these criteria,polymyositis is defined as Definite All of criteria 1-4 Probable Any three of criteria 1-4 PossibleAny two of criteria 1-4 Dermatomyositis defined as definite5 plus any three of criteria 1-4 Probable 5 plus any two of criteria 1-4 Possible 5 plus any one of criteria 1-4 36. Exclusion criteria for PM/DM Evidence of any central or peripheral neurologic disease Muscle weakness with slowly progressive course, and family history ofcalf enlargement to suggest muscular dystrophy Biopsy with granulomatous myositis, such as with sarcoidosis Evidence of active infection Recent use of drugs known to be toxic to muscles cocaine, statins, fibrates, etc. Overt rhabdomyolysis Glycogen storage disorders (i.e. McArdles) Endocrinopathies hypo-/hyper- thyroid/parathyroid, diabetes, Cushings Myasthenia Gravis 37. Treatement Prednisone 1mg /kg/day4to 6weeks Tapering 5 to 10 mgmonthly Improve in musclestrength Decrease CK level 38. Cont.. Immunosupperesive If do not improve Steroid side effect Poor prognostic factor MethotrexateIVIGRituximab 39. Cont High Protien Diet Activity and Exerciseshould be encouraged