Clinical Features for Mild Hand, Foot and Mouth Disease in China

BACKGROUND Mild hand, foot and mouth disease (HFMD) is at a critical stage owing to its ease of communicability and a higher risk of developing severe complications and death. Clinical diagnosis of mild HFMD was made by the presenting symptoms and signs (symptoms in brief) alone. We aim to evaluate the frequencies of symptoms in a retrospective case series study. METHODS We collected epidemiological, demographic, clinical, and laboratory data from outpatient and inpatient settings on the clinical data warehouse system. We principally described the frequencies of symptoms of mild HFMD. Correlations between symptoms with laboratory-confirmed cases were then analyzed. RESULTS The clinical data warehouse system included 3649 probable cases, between 2010 and 2012, of which 956 (26.20%) were laboratory confirmed. The peak incidence was identified in children 2 years of age. A total of 370 of the 956 laboratory confirmed cases (38.70%) were associated with enterovirus 71 (EV71). Logistic regression analysis adjusted for geographical variables, age, sex, month of onset, and time from onset to diagnosis showed that the clinical features constipation (P<0.0001; adjusted OR, 95%CI (2.99, 2.28-3.91)), and blisters (P<0.0001; adjusted OR, 95%CI (2.16, 1.82-2.56)) were positively correlated with the confirmed cases. CONCLUSIONS This is the largest case series study, including all the guideline-mentioned symptoms of mild HFMD. Our findings suggest that blisters and constipation should be considered as potential warning signs while front-line clinicians manage surges of children diagnosed with mild HFMD during a pandemic.