Dr.Sruthi, Dr.Sajitha Nair, Dr.Suma Balan (Pediatricrheumatology), Dr.C.Jayakumar
Amrita Institute of Medical Sciences, Kochi
Twelve year old male presented with intermittent episodes of high grade fever which started three months back associated with an evanescent rashes, pain and swelling of both knees. He was on steroid from an outside hospital and showed good response for around 1 month.
Off his symptoms recurred.
At admission, he was febrile and sick looking with other stable vitals.
Auxology: Weight: 46.3 kg (At 0 SD), Height: 155 cm (b/w 0 and +1 SD), BMI: 19.27 Kg/m2 (b/w 0 and +1 SD).
Examination revealed non-pruritic evanescent erythematous flat rashes over bilateral arms, legs and abdomen.
Abdominal examination revealed hepatomegaly.
Musculoskeletal system examination revealed bilateral knee effusion with painful range of movements.
Picture showing erythematous evanescent rashes over arms
Blood investigations showed very high inflammatory markers (CRP: 235mg/L, ESR: 102mm/1st hr), neutrophilicleukocytosis (TC-17.89ku/ml, NC-84%, LC-10%), microcytic hypochromic anemia (Hb: 11.2g/dl) with thrombocytosis (platelets: 423ku/ml), high ferritin (2115 ng/ml), and hyperglobulinemia (4.47g/dl) with AG reversal. Transaminase levels were normal, and fibrinogen levels were high. In view of hyperglobulinemia, Serum IgG and IgE levels were measured, showing high IgG (1619 mg/dl) and IgE(640IU/ml).
Complement levels and anti-dsDNA were also checked, showing high C3 (219mg/dl) with normal C4 and normal dsDNA.
Differentials
Systemic juvenile idiopathic arthritis (SOJIA),
Dengue fever
Rheumatic fever
Harmatological malignancy
Infective workup was negative (IgM leptospira, blood culture, urine culture, salmonella). Peripheral smear was also normal.
No definite generalized lymphadenopathy was found clinically and sonologically. There were no features of leukopenia or thrombocytopenia.
Screening ECHO did not show any signs of vegetation or valvular involvement, and there was no clinical history or examination consistent with rheumatic fever, thus ruling out other possibilities.
A diagnosis of SOJIA was thus made, and initially, the child was started on naproxen and monitored. However, as fever spikes persisted with arthritis and hiking ferritin, the possibility of Macrophage Activation Syndrome was considered, and the child was pulsed with IV steroids and later transitioned to oral steroids. The child showed marked clinical improvement in fever and arthritis.
Labs also showed down trending of inflammatory markers and counts.
Systemic-onset juvenile idiopathic arthritis (SOJIA) is a subtype of juvenile idiopathic arthritis (JIA) characterized systemic inflammation and arthritis. It typically presents with high-grade, intermittent fever, evanescent salmon-coloredrashes, and arthritis affecting multiple joints. Additional clinical features may include hepatosplenomegaly, lymphadenopathy, and serositis. Laboratory findings often show elevated inflammatory markers, such as CRP and ESR, along with leukocytosis, thrombocytosis, and hyperferritinemia. The diagnosis is clinical, supported the exclusion of infections and malignancies. Treatment often involves nonsteroidal anti-inflammatory drugs, corticosteroids, and biologic agents targeting interleukin-1 and interleukin-6 pathways, aiming to control inflammation and prevent long-term joint damage.
Clinicians should maintain a high index of suspicion for SJIA in similar presentations and consider the possibility of macrophage activation syndrome (MAS) in patients with persistent fever and rising inflammatory markers despite initial treatment. Early and aggressive management can significantly improve clinical outcomes and quality of life for these patients.