Fang Guo, Lei Kang, Bo Li, Yanhong Jia, Xiaoyuan Wu
HNL-AM/ME predominantly affects school-aged boys. Typical features include recurrent fever, headache, leukopenia, CSF pleocytosis, linear sulcal FLAIR hyperintensity, LME, poor response to anti-infective therapy, and favorable response to glucocorticoids. Younger children (<6 years) with markedly elevated ferritin, and brain parenchymal involvement, may have a higher risk of severe disease. Early diagnosis and glucocorticoid therapy improve prognosis.
BACKGROUND AND PURPOSE: Aseptic meningitis (AM) and meningoencephalitis (ME) is a rare and under recognized complication of histiocytic necrotizing lymphadenitis (HNL) in children, with no large-scale series reported. The present study aims to characterize the clinical features of HNL-AM/ME and improve recognition of this condition.
METHODS: We retrospectively analyzed the clinical data of children with HNL-AM/ME admitted from January 2018 to January 2026, summarizing their clinical manifestations, laboratory findings, brain magnetic resonance imaging (MRI) findings,and treatment protocols.
RESULTS: Among 797 children with HNL, 26 met criteria (23 AM, 3 ME), with a male-to-female ratio of 4.2:1. Median age at onset for all cases was 10.0 years (IQR, 6.8-12.0 years), but all ME cases were ≤6 years. All 26 presented with fever and lymphadenopathy, with a median fever duration of 26.5 days (IQR, 18.0-35.3 days), and only 4 (15.4%) cases defervesced before glucocorticoids, while neurological symptoms were the initial manifestation in 11 (42.3%) cases. Leukopenia was observed in 20 (76.9%) cases. Elevated serum ferritin (>500 μg/L) was found in 5 (19.2%) cases. All 26 patients had cerebrospinal fluid (CSF) pleocytosis (median 57.0/μL; range 16-529/μL). Elevated CSF pressure (220-280 mmH2O) was noted in 10 children, and CSF protein was increased in 12 children. Nine (30.8%) cases exhibited linear hyperintense signals along segments of the cerebral sulci on fluid-attenuated inversion recovery (FLAIR) sequences. Only 5 patients underwent gadolinium-enhanced brain MRI, with 3 showing leptomeningeal enhancement (LME). A total of 24 cases (92.3%) received glucocorticoid treatment, 7 cases (26.9%) were combined with IVIG, and 3 ME children received immune enhancement treatment. Recurrence occurred in 8.3% (2/24) of glucocorticoid-treated patients, whereas both untreated patients relapsed. Of the 3 ME children, 2 developed epilepsy, and 1 concurrently developed macrophage activation syndrome (MAS).
CONCLUSION: HNL-AM/ME predominantly affects school-aged boys. Typical features include recurrent fever, headache, leukopenia, CSF pleocytosis, linear sulcal FLAIR hyperintensity, LME, poor response to anti-infective therapy, and favorable response to glucocorticoids. Younger children (<6 years) with markedly elevated ferritin, and brain parenchymal involvement, may have a higher risk of severe disease. Early diagnosis and glucocorticoid therapy improve prognosis.