What Causes Rash All Over The Body?

Hi I am 50 years old still on the pill im experiencing hot flashes at night and i am itching over my entire body i have what looks like prickly heat rash but know it is not i have had the itching now for about 4 months everyday dont know if i should stop taking the pill, pregnancy is not an issue. only taking pill for heavy bleeding during menstral periods. i have gained 10 pounds in 4 months what do you recommend?