For itchy skin and hives, suggestions that seemed to work for me:
1. Wear only hypo-allergenic clothing, i.e. cotton.
2. Wash clothing in a perfume-free detergent and rinse very well before
tumble drying -- yes, do this yourself.
3. Wash your skin with mild soap (Ivory) and rinse very well in shower;
tea-tree oil or coal-tar shampoo (anti-dandruff) might help.
4. Apply lotions and try OTC hydocortisone cream and/or topical
administration of benadryl.
-bg

When I wash my clothes I mix fabric softener 50/50 with plain white
vinegar to reduce the alkalinity of any leftover detergent.

What made a huge difference for me on treatment was to keep myself as
buttered up as a well-basted thanksgiving turkey.

What worked the best for me was Gold Bond Ultimate Healing Body Lotion.

After a shower when I was still slightly damp I'm slather it all over my
body.  Feels really thick but then soaked in and made the bumps
disappear in a couple of days.  Even my elbows became completely smooth.

Sometime after that my mouth started to get irritated and I'd use
Biotene mouthwash a couple of times a day.  That helped a lot too.

G.