Swelling, rash, and blisters

My cousin has been having this rash for two months now and it is all over her body, it is starting to get on her face now too.  This rash is warm and causes heat to her inside her body.  She can't be outside or she starts itching a lot.  Now her legs are getting swollen.  Last night, her legs got numb and she could not move her legs, they got really heavy.  She was outside and then she went inside the house into a room where it was warm, it was not cool.  What treatment do you recommend for her to do?

[dloveJJJ]

MAYBE GO TO A SPECIALIST WOULD BE THE BEST ANSWER..