Both my children and I contracted herpangina, which is a strain similar to HMFD except that there are no blisters on hand and feet. High fever and ulcers/blisters in mouth. It's an extremely stressful episode and I had high fever for 3 days and can barely swallow saliva.
I find these help during my ordeal:
1) drink ice cold water as it helps numb the pain, and the only painless way up put fluid in body
2) eat cold soya bean curd. My son was willing to eat this because it was sweet and cold
3) keep washing hands and make sure you practice proper hygiene
4) panadol helps to manage the pain
5) If children refuse to eat, put Ribena or 100plus in freezer and let the children drink to keep them hydrated