Objective  To study the diagnostic value of combined detection of serum amyloid A (SAA), C reactive protein (CRP) and white blood cell count (WBC) on hand-foot-and-mouth disease (HFMD) in children.

  Methods  A total of 138 children with HFMD from May 2018 to May 2019 in our hospital were as HFMD group, and were divided into general subgroup (n=122) and severe subgroup (n=16) according to the severity of disease. Fifty healthy children at the same period were included in control group. The levels of serum SAA, CRP and WBC were compared among the subgroups and between HFMD group and control group. The diagnostic values of detection of SAA, CRP, WBC alone and combined detection in diagnosis of HFMD were evaluated by using receiver operating characteristic curve(ROC curve).

  Results  The levels of serum SAA, CRP and WBC in general group were lower than those in severe group (P < 0.05), and were higher in HFMD group than those in control group (P < 0.05). Serum SAA, CRP and WBC levels were closely related to whether research objects had HFMD or not(P < 0.05). The ROC curve of SAA showed area under the curve(AUC) was 0.952 (P < 0.05), and the cut-off value was 11.07 mg/L, and the sensitivity and specificity were 0.899 and 0.860 respectively. The ROC curve of CRP showed AUC was 0.914 (P < 0.05), and the critical value was 9.47 mg/L, and the sensitivity and specificity were 0.848 and 0.920 respectively. The ROC curve of WBC showed AUC was 0.709 (P < 0.05), and the critical value was 10.00×10⁹/L, and the sensitivity and specificity were 0.609 and 0.900 respectively. The AUC, sensitivity and specificity of combined detection were 0.989, 0.957 and1.000 respectively, which were better than those of detection alone(P < 0.05).

  Conclusion  The elevated levels of serum SAA, CRP and WBC are closely related to the occurrence and development of HFMD. Combined detection has certain value in the diagnosis of HFMD.