Macrophage activation syndrome secondary to systemic juvenile idiopathic arthritis with coronary involvement in a pre-school patient. Case report and literature review

Abstract

DOI: 10.1016/j.rcpe.2015.11.001

Systemic juvenile idiopathic arthritis (SJIA) is one of the most common chronic diseases in children. In spite of having well-defined clinical manifestations, the diagnosis of SJIA remains a clinical challenge as it requires previously ruling out infectious, neoplastic or inflammatory type conditions, in the context of the patient with fever of unknown origin. Coronary involvement on SJIA has been demonstrated in about 10% of cases. The macrophage activation syndrome (MAS) is a complication of SJIA that can be potentially fatal if an appropriate approach and treatment is not performed.

The case concerns a pre-school infant with no significant medical history, with clinical symptoms of 12 days onset, characterised by intermittent fever, associated with cough, rhinorrhoea and skin manifestations (generalized exanthema) and oral cavity plaques. During clinical evolution, Kawasaki syndrome symptoms were considered, based on clinical criteria and subsequently supported by echocardiogram findings (dilation of coronary arteries). A total of 2 doses of human immunoglobulin were given, with no clear improvement in the clinical symptoms and laboratory parameters. Glucocorticoids and immunomodulatory management therapy was then started. The patient was finally diagnosed with a macrophage activation syndrome, based on laboratory parameters in the context of an autoimmune disease, such as systemic juvenile idiopathic arthritis. A satisfactory clinical outcome was obtained with outpatient treatment.

SJIA remains a disease that is difficult to diagnose early. To distinguish this entity from other rheumatological conditions, mainly Kawasaki disease, remains a diagnostic challenge in pediatrics. It requires great ability to recognize this disease and initiate its respective treatment in a timely manner in order to avoid fatal outcomes as a result of complications.