Still's Disease in a Pediatric Patient after Liver Transplantation

Still's disease (SD) is a multisystemic inflammatory disease characterized by persistent arthritis and in many cases with fever of unknown origin. Diagnosis of SD is challenging because of nonspecific characteristics and especially in the case of a patient with solid organ transplantation and immunosuppressive therapy where multiple causes of fever are possible. There is no diagnostic test for SD, even though some useful diagnostic criteria or laboratory findings, such as serum ferritin levels, have been proposed, and useful imaging studies for the diagnosis or followup of SD have not been developed. We report the case of a 9-year-old child who presented with high grade fever associated with joint pain after a history of liver transplantation and immunosuppressive therapy. Laboratory tests showed increased acute phase reactants, elevated ferritin, and leukocytosis. An 18 F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) was performed identifying abnormal hypermetabolic areas localized in spleen, transplanted liver, and bone marrow secondary to inflammatory process. All infectious, autoimmune, and malignant causes were ruled out. A diagnosis of SD was performed and a steroid-based regimen was initiated with adequate response and no evidence of recurrence. To our knowledge this is the first case of SD following a solid organ transplant. 1. Introduction Systemic juvenile idiopathic arthritis (JIA) or Still’s disease (SD) is a multisystem inflammatory process that usually presents with high fever, a classic faint salmon-colored skin rash, arthritis, and variable systemic features like lymphadenopathy, serositis, odynophagia, and hepatosplenomegaly. The pathogenesis and etiology of SD have not yet been clearly determined [1]. Diagnosis of SD is challenging because of its low prevalence, heterogeneous clinical manifestations, and absence of pathognomonic clinical features [2]. Significant laboratory abnormalities include marked leukocytosis, thrombocytosis, and anemia in association with elevated acute phase reactants such as C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and serum ferritin which reflect an important systemic inflammatory response [3]. It is important to rule out a wide range of other diseases including infectious, malignant, and other rheumatic diseases, especially if fever occurs in patients with immunosuppressive conditions. Several studies have demonstrated the clinical value of using 18 F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) scans to aid in the diagnosis of SD [4]. Here, we report a