Co-occurrence of Griscelli Syndrome Type 2 and Systemic Juvenile Idiopathic Arthritis in a Pediatric Patient: A Case Report.

Griscelli syndrome type 2 (GS2) is a rare autosomal recessive immunodeficiency disorder characterized by silver-colored hair, fair skin, and an increased risk of developing hemophagocytic lymphohistiocytosis (HLH). Systemic juvenile idiopathic arthritis (sJIA) is an autoinflammatory condition distinguished by daily fevers, transient rash, and arthritis, with macrophage activation syndrome being a known complication. We present a case involving an 18-month-old female with persistent fever, rash, and joint inflammation. Laboratory findings revealed elevated inflammatory markers and hyperferritinemia, prompting concern for HLH, though full diagnostic criteria were not satisfied. A unique clinical sign led to extended evaluation, and genetic testing confirmed the presence of GS2. Concurrent clinical features also met the requirements for sJIA. To the best of our knowledge, this is the first reported instance of GS2 co-occurring with sJIA. This case highlights a potential shared susceptibility to immune dysregulation and raises the possibility that immunodeficiency may reveal or influence the manifestation of autoinflammatory diseases. Prompt recognition is essential in managing atypical and treatment-resistant inflammatory presentations.