Smitty,
I don't know what chemo he is taking but my Dad had blister like sores in his scalp as well. He was taking Erbitux and they said that is what caused it. He had these even three weeks after chemo was over. The suggested using a over the counter shampoo - I can't remember the name but I think it was something like serum blue, basically it dried them up. They also gave him an antibiotic for the acne rash that he had all over his face and neck and scalp from the Erbitux. Tell him to hang in there - this is a rough treatment but taking it one day at a time like Michele said is very good advice. Look at each day as an accomplishment and don't get too far ahead of yourself.
God bless
Kim