AB0218 Amyopathic dermatomyositis associated with pneumonitis: is methotrexate a risk factor ?

Abstract

Objectives We describe a patient with multicentric reticulohistiocytosis whose manifestations have started at a much younger age than mentioned in the literature. Methods Results 18-year-old female patient presented with a complaint of arthralgia at her wrists, knees and ankles. Her complaints had started 6 months before admission with arthralgia and painful swellings at the wrists and kness. On admission she had active symmetric arthritis at the shoulders, elbows, wrists and knees. Synovial hypertrophy was prominent at the wrists, knees and MCP joints. Cutaneous examination showed a single 0.5 × 0.5 cm erythematous nodular structure at her 3 MCP joint. There were orange coloured hypertrophic lesions at her nail-folds. Her systemic examination was not remarkable. Her ESR was 29 mm/ h, CRP 96 mg/dl, RF(-), Hb: 11.5, WBC: 10.300, platelets 289.000. Liver and kidney functions were normal. x-rays of the hands showed periarticular osteopenia, there were no erosions. Arthrosyntesis showed the characteristics of an inflammatory synovial fluid. She was thought to have active rheumatoid arthritis and was started on 7.5 mg prednisolone and sulphasalazine 2 g/day. The dosage of prednisolone was gradually increased to 30 mg/day as there was no improvement in her active arthritis. Methotrexate 7.5 mg/week was added. During her follow-up she developed orange papulonodular lesions on her forehead and pinnae. Biopsy taken from the 3MCP joint revealed reticulohistiocytoma. 10 months after the diagnosis she is still under close surveillence as the disease can be associated with malignancy in 25% of patients. She is currently on methotrexate 12.5 mg/week and prednisolone 20 mg/day. The active arthritis at the shoulders and knees has resolved but she still has active arthritis at the wrists. Conclusion Although multicentric reticulohistiocytosis affects predominantly middle-aged women the disease should be kept in mind in the differential diagnosis of active arthritis for younger age groups as well.