That's a tough one. I see posts like that on the allergy and sci.med newsgroup
It can range from an allergy to soap, not rinsing clothing properly,
"neuropathy", a side effect of meds, or something growing in or near your home
or workplace (mould, plants), sweating and yeast (maybe)
dry skin, lice, foods, right through to Lupus or one type of cancer - assuming
the lesions are occuring from scratching, (I saw itching mentioned with one
yesterday, but I forget which). I think I saw someone on another newsgroup who
was taking something herbal that had stinging nettle in it which can cause
itching in some.

As best I can tell is you have to do a process of elimination (while treating
the symptoms) and keep a diary.
It's work and it's not something that doctors can do for you.

If you want to eliminate dry skin and lice, have a laundered (hot water) set of
clothing in your car, spend a few nights at a motel totally away from home and
make sure you have a non-allergic oil for dry skin like baby oil.  If the
itching stops or starts to abate, then you know the problem is somewhere at your
home.
If the itching stops or is not as bad on weekends or during a week's holiday,
then you have a hint that the problem might be at work.
If you want to rule out Lupus or sun allergy, stay totally covered up (away from
any source of UV rays/lighting) for a few days and see if the itching improves.

You could also consult an allergist and/or dermatolgist, but the more you can do
first, the less frustrating it would be for all parties involved.

You've posted before here, but I can't ascertain what type of cancer you had,
treatments if applicable etc.
J

Have you been checked for Sezary Syndrome - the leukemic form of cutaneous
t-cell lymphoma

Call your closest teaching hospital and ask to be evaluated by whomever in
the dermatology or oncology dept. regularly sees Sezary patients. Sezary is
very rare, but if you are a Vietnam era vet, you run a higher than normal
risk of having Sezary. From your brief description, you have all the
symptoms and are the correct age. Sezary is often misdiagnosed. A blood test
for Sezary cells and skin evaluation will tell for sure.              hope
this helps,    s2d

--
"Dissent is the highest form of patriotism"   Thomas Jefferson

"May we never confuse honest dissent with disloyal subversion"     Dwight D.
Eisenhower