Journal of Clinical Case Reports

System Onset Juvenile Idiopathic Arthritis Evolving into Macrophage Activation Syndrome in a Child with Pyrexia of Unknown Origin

Abstract

Sanjukta Mukhopadhyay* and Ajitesh Singh

Macrophage activation syndrome is a potentially life-threatening complication of rheumatic diseases. Here, we report the case of a 4-yearold boy who presented with fever for 5 months, initially moderate-high grade, abdominal pain for 3 months, and pain in BL knee and ankle joints for 2 months. On examination, the child had multiple cervical lymphadenopathies and no organomegaly. The differential of disseminated tuberculosis, lymphoma, and juvenile idiopathic arthritis. The initial blood count was normal. The Chest X-Ray was also normal. Bone marrow examination showed normal hematopoiesis. The excisional biopsy of the cervical lymph node showed reactive lymphadenitis. During the course of hospitalization, the patient developed high-grade fever with hepatosplenomegaly and swelling of BL ankle and knee joints. The blood count at 2 weeks suggested pancytopenia, and liver function test indicated increased aspartate aminotransferase. Chest X-Ray showed BL pleural effusion, a clear transudative fluid was aspirated. C-Reactive protein, serum ferritin, and triglycerides were raised, and his bone marrow exhibited hemophagocytosis, while the Erythrocyte sedimentation rate and fibrinogen levels were decreased. Based on ILAR (International league against Rheumatism’s) and PRINTO (Paediatric Rheumatology International Trials Organisations) criteria, a diagnosis of Systemic onset juvenile rheumatic arthritis with macrophage activation syndrome was made. The patient was managed with intravenous methylprednisolone, intravenous immunoglobulin, and tacrolimus. The patient showed gradual clinical improvement and was discharged on clinical improvement and was doing well on follow-up at 4 weeks and 6 months.