Clinical features and dynamic ordinary laboratory tests differentiating dengue fever from other febrile illnesses in children

Background Dengue fever is not easily to be diagnosed before presentation of the classic symptoms. The study aimed to investigate the clinical features and dynamic laboratory tests in pediatric patients to facilitate dengue diagnosis. Methods This retrospective study examined the medical records of all pediatric patients who were clinically suspected to have dengue from June to December 2014. Laboratory-positive dengue cases were confirmed by detecting non-structural protein NS1, reverse transcription-polymerase chain reaction of dengue virus, and dengue-specific IgM seroconversion. Results Of the 317 pediatric cases clinically suspected of dengue, 205 were laboratory-positive and 112 were laboratory-negative. In laboratory-positive cases, the most common clinical manifestation was skin rash in 156 (76.1%). Leukopenia occurred on days 1–5; thrombocytopenia, on days 2–7; prolonged activated partial thromboplastin time (aPTT), on days 1–4; and elevated transaminase levels, on days 3–11; and low CRP, on days 0–14. The specificity and positive predictive value (PPV) of combining of rash, itching and petechiae increased up to 100%. The PPV of combining of leukopenia, thrombocytopenia, and elevated transaminase levels reached 100% on day 2 as well as days 6–8. Conclusion Leukopenia, thrombocytopenia, elevated aPTT, elevated transaminase levels, and low CRP could be used to differentiate dengue fever from other febrile illnesses. During dengue epidemics, combinations of the symptoms and laboratory findings are helpful to physicians for accurate diagnosis of dengue fever.