Dexa-Myositis Trial: treatment of polymyositis and dermatomyositis - dexamethasone versus prednisone

INTERVENTION: 1. Dexamethasone pulse therapy. 40 mg/dag every first four days of the month, for 6 months. Placebo on the other days of the months. 2. Prednisolone 1 ‐ 1.5 mg/kg/day for 4 weeks, after this slow reduction in dose Both groups treatment against osteoporosis with calci‐chew and Fosamax. CONDITION: Myositis, dermatomyositis, polymyositis ; Musculoskeletal Diseases ; Myositis PRIMARY OUTCOME: 1. Combined scale: Rankin, muscle strength, Visual Analogue Scale (VAS) pain, time until remission, no relapse, no cushing, no osteoporosis; 2. Percentage patients in remission, time to remission, no relapse; 3. General assessment of condition of patients SECONDARY OUTCOME: 1. Weight; 2. Blood pressure; 3. VAS arthralgia, Raynaud; 4. Skin changes; 5. CK; 6. Myometry; 7. VAS dysphagia; 8. VAS agitation; 9. Quality of life; 10. Medication and dose; 11. Other side effects; 12. Neuromusclular symptom score INCLUSION CRITERIA: 1. Polymyositis 2. Dermatomyositis 3. Myositis with rheumatological disorders 4. Myositis with cancer 5. Unspecified myositis