Objective: To analyze the clinical features, treatment, outcomes, and risk factors influencing the duration of fever in children and adolescents with histiocytic necrotizing lymphadenitis (HNL). Methods: A retrospective analysis was conducted on the clinical data of 35 pediatric HNL patients admitted to the First Affiliated Hospital of Nanjing Medical University. The clinical characteristics and risk factors were compared between a short-duration fever group (≤2 weeks, n=17) and a long-duration fever group (>2 weeks, n=18). Results: Among the 35 patients, the mean age was 14.69 ± 2.42 years, with a male-to-female ratio of 1.06:1. All cases presented with lymphadenopathy, with cervical lymphadenopathy in 85.7%, tenderness in 74.3%, and fever in 97.14%. Common laboratory abnormalities included elevated lactate dehydrogenase (65.7%), increased erythrocyte sedimentation rate (65.7%), leukopenia (62.86%), neutropenia (51.43%), elevated high-sensitivity C-reactive protein (54.29%), and elevated ferritin (45.71%); 17.1% of patients tested positive for antinuclear antibody. The long-duration fever group had higher proportions of extra-cervical lymphadenopathy, leukopenia, neutropenia, antinuclear antibody positivity, and elevated inflammatory markers (P < 0.05). Logistic regression indicated that elevated ferritin was independent risk factor for prolonged fever duration. Antibiotics were ineffective in all 27 patients who received them. In 22 patients treated with glucocorticoids post-biopsy, the mean time to defervescence was 3.82 ± 4.79 days, with the short-duration fever group showing faster fever resolution (P < 0.05). During follow-up ranging from 6 months to 2 years, recurrence occurred in 2 patients, and none progressed to autoimmune diseases. Conclusion: HNL in children and adolescents primarily manifests with fever, painful cervical lymphadenopathy, leukopenia, and an elevated erythrocyte sedimentation rate. Elevated ferritin is independent risk factor for prolonged fever duration. Diagnosis relies on lymph node biopsy, antibacterial therapy is generally ineffective, and glucocorticoid treatment demonstrates favorable efficacy.