I Have A Very Itchy Rash On My Hips And

I have a very itchy rash on my hips and pelvis around my genitals. When I scratch it, tiny red bumps appear. Hot water in the shower makes it worse, and it seems to be worse at night. Also I know I caught it from my girlfriend as a lot of people at her nursing home, including her have similar symptoms. What do you think this is? Some of her co workers got treatment for scabies, but it didn't go away.