What Causes Severe Itching Problem All Over The Body?

I am having severe itching problem all over my body from past 1 months. Red rashes started coming over the itching place. I am doubtful that it might be a cause of reaction from the injections(PROHALE....Natural Micronised Progesterone) for my pregenancy I am taking from past few weeks. Please suggest the solution and effective medicine to comeoff from this itching?

Thankx

Liza