Systemic Juvenile Idiopathic Arthritis: A Challenging Diagnosis
Systemic juvenile idiopathic arthritis (SJIA) is a disease challenging to diagnose. Its onset can be quite nonspecific, suggesting other entities. The authors present the case of a 17-year-old adolescent, with a clinical picture lasting for 5 months characterized by intermittent polyarthritis and myalgia, associated with fever and exanthema some months later. During clinical investigation, elevation of inflammatory markers was found, and infectious, oncologic and other autoimmune diseases were excluded. This patient also met criteria compatible with macrophagic activation syndrome secondary to SJIA. This entity implies a high index of suspicion and should be early recognized by the clinician because of its implications in terms of morbidity and mortality.