Analysis of Clinical Features of Non-infectious Inflammatory Fever
Authors: LI Shan , TIAN Qilong , ZHOU Yun , ZHANG Yan , LIAN Jianqi 
Published: November 2023

Background
Fever of undetermined origin (FUO) is a challenging entity with a striking presence in hospitals around the world. It is defined as temperature ≥ 37.8 ° C on several occasions, lasting ≥ three weeks, in the absence of diagnosis after three days of hospital investigation or 3 outpatient visits. The main etiologies are infectious, neoplastic, and non-infectious inflammatory diseases. At present, the clinical characteristics of non-infectious inflammatory diseases are less well described, the aim of this study is to analysis the features of non-infectious inflammatory diseases, more efficient differential diagnosis of FUO.
Methods
A total of 444 patients with non-infectious inflammatory fever were retrospectively studied, and another 133 patients with infectious fever act as control group, to analysis the clinical features of non-infectious inflammatory fever.
Results
The pathogenesis (212.47 ± 38.40 vs 105.52 ± 37.58) days of non-infectious inflammatory fever were longer than infectious fever(p < 0.05), and the levels of white blood cells (8.80 ± 0.27 vs 7.02 ± 0.32) x109/L, neutrophils (6.78 ± 0.25 vs 4.80 ± 0.24) x109/L, platelets (277.85 ± 6.23 vs 241.50 ± 8.47) x109/L, erythrocyte sedimentation rate (73.08 ± 1.65 vs 54.90 ± 3.23)mm/h, lactate dehydrogenase (311.29 ± 13.21 vs 248.21 ± 12.56)U/L, alpha-hydroxybutyrate dehydrogenase (233.94 ± 9.02 vs 188.35 ± 8.70)U/L, and ferritin (1008.37 ± 117.18 vs 509.38 ± 49.18) µg/L were increased obviously in non-infectious inflammatory fever group patients(p < 0.05), but the levels of red blood cells (3.63 ± 0.03 vs 6.28 ± 2.37) x1012/L, hemoglobin (101.98 ± 0.86 vs 113.90 ± 1.95) g/L, lymphocytes (1.35 ± 0.03 vs 1.55 ± 0.14) x109/L, and lymphocyte to C-reactive protein ratio (0.20 ± 0.04 vs 0.52 ± 0.17) were dropped (p < 0.05), and the positive rate of anti-nuclear antibodies(54.95% vs 30.08%), anti-RNP/Sm antibodies(14.19% vs 0.75%), anti-ds-DNA antibodies(8.33% vs 0%), anti-Sm antibodies(14.41% vs 0%), anti-nucleosome antibodies(8.56% vs 0%), anti-histone antibodies(4.73% vs 0%), anti-ribosomal P protein antibodies(6.98% vs 0%), anti-SSA antibodies(20.04% vs 5.26%), anti-SSB antibodies(6.76% vs 1.50%), and anti-Ro-52 antibodies(17.57% vs 3.76%) in non-infectious inflammatory fever patients were higher than infectious fever patients (p < 0.05), the concomitant symptoms of feeble(18.92% vs 11.28%), arthralgia(33.78% vs 21.05%), skin rash(11.71% vs 4.51%), and lower limb edema(4.73% vs 0%) were higher incidence in non-infectious inflammatory fever patients(p < 0.05), but the headache(4.28% vs 13.53%) was lower incidence in non-infectious inflammatory fever patients(p < 0.05), the incidence of pericardial effusion(15.54% vs 5.26%) was higher in non-infectious inflammatory fever patients(p < 0.05), but the incidence of pleural effusion(0.45% vs 8.27%) was lower in non-infectious inflammatory fever patients(p < 0.05).
Conclusion
The patients of non-infectious inflammatory fever have longer pathogenesis, and the levels of white blood cells, neutrophils, platelets, erythrocyte sedimentation rate, lactate dehydrogenase, alpha-hydroxybutyrate dehydrogenase, and ferritin were increased, the levels of red blood cells, hemoglobin, lymphocytes, and lymphocyte to C-reactive protein ratio were dropped, many autoantibodies were included, and the incidence of feeble, arthralgia, skin rash, lower limb edema, and pericardial effusion were higher, but the incidence of headache and pleural effusion were lower.