R.S.
I don't know much about H.F.M.D but for the fever this really works. It sounds like an old wives tale but on my children adn my best friends children who could not break their fevers, It really worked.
(depending on where blisters are)
Get Vicks vapor rub CREAM (childrens), and rub it in behind there knees, bottoms of feet, and thier elbows at bed time. You may have to do this a couple of bed times, but in most instances, mine & my best friends case, one time only worked to break the fever.