CD19 and hand, foot and mouth disease: Whether and when systemic glucocorticoids should be used to treat high fever, like that experienced by severe and very severe HFMD patients, is still controversial; when we examined 3 severe HFMD patients at the height of high fever in our study population that were not treated with glucocorticoid treatment, no significant or even slight increase in CD19+HLA-DR+ cells was found (data not shown).