Macrophage Activation Syndrome secondary to Systemic Juvenile Idiopathic Arthritis: A Case Report

Area of Science:

• Pediatric Rheumatology
• Immunology
• Critical Care Medicine

Background:

• Macrophage activation syndrome (MAS) is a rare, life-threatening hyperinflammatory condition.
• It is most commonly associated with Systemic Juvenile Idiopathic Arthritis (sJIA).
• MAS presents with non-specific symptoms, often delaying diagnosis.

Observation:

• A 12-year-old male experienced persistent fever unresponsive to antibiotics.
• Extensive investigations were conducted to exclude other diagnoses.
• The patient was ultimately diagnosed with MAS secondary to sJIA.

Findings:

• Key clinical features of MAS include fever, hepatosplenomegaly, hypertriglyceridemia, hypofibrinogenemia, hyperferritinemia, and impaired liver enzymes.
• The patient's non-specific symptoms mimicked other febrile illnesses, complicating initial assessment.
• Diagnosis relied on a comprehensive evaluation of clinical and laboratory findings.

Implications:

• Prompt recognition and management of MAS are critical for patient survival.
• Systemic Juvenile Idiopathic Arthritis requires vigilant monitoring for potential MAS development.
• Steroid therapy is a primary treatment modality for MAS, demonstrating efficacy in this case.