Hello,
The itchy red rashes are due to hives. Hives (medically known as urticaria) are red, itchy, raised areas of skin that appear in varying shapes and sizes. They have a tendency to change size rapidly and to move around, disappearing in one place and reappearing in other places, often in a matter of hours.
Take some antihistaminic like Benadryl or Claritin and apply some calamine lotion on the rashes. If the symptoms persist then topical or oral steroids may be needed. Please consult a dermatologist in that case.
I hope it helps. Take care and please do keep me posted in case you have any additional doubts. Kind regards.
That could be a psoriasis flare, but it depends on whether or not she has flakes. Does she have a history of this happening? Psoriasis is essentially inflamed skin, so it would feel hotter than unaffected skin. HOWEVER, it could also be something much more serious, if it is inching across the skin rapidly- a severe infection, even. I would visit a dermatologist post haste, especially if she has flu-like symptoms.