Unusual presentation and rare association of pediatric lupus

Abstract

Systemic lupus erythematosus (SLE) is a chronic multisystem autoimmune inflammatory disorder with diverse clinical manifestations which can lead to significant morbidity and mortality. Children and adolescents represent 15% to 20% of all patients with SLE. Childhood onset SLE is a rare disease with a prevalence of 3.5 to 8.8 per one lakh children. Localized or generalized lymphadenopathy may be an uncommon presenting feature of SLE. None of the classification criteria for SLE include lymphadenopathy as a criterion including the latest 2019 American college of rheumatology (ACR) / European league against rheumatism (EULAR) criteria. Nine-year-old female child presented with history of swelling on both sides of neck associated with fever and easy fatiguability for 2 months. Clinical examination revealed significant bilateral cervical and axillary lymph nodes with hepatomegaly. Excision biopsy of lymph node was suggestive of Kikuchi Fujimoto disease (KFD). As rare association of KFD with SLE is well described in literature, despite negative clinical features and laboratory findings of SLE, including an initial negative ANA IF test, we did a repeat ANA IF, complement (C3) level and dsDNA testing, all of which turned out to be positive, confirming the diagnosis of SLE. The child was started on hydroxychloroquine and oral steroids with dramatic response. During steroid tapering she developed a flare needing the addition of azathioprine. Currently she is in remission and is under follow up. Although rare, lupus lymphadenopathy may be a presenting feature of SLE. This can even antecede the diagnosis of SLE by many years, when the presence of auto antibodies or low complement levels are not detected and are associated with higher disease activity. This emphasizes the importance of high index of suspicion of SLE in cases of lymphadenopathy, enabling early diagnosis and management which is essential for preventing morbidity and mortality.