Rash on Hips

I’m 3 months PP and over the last few days have developed a rash. My arms are extremely itchy but the bumps don’t have any colour. I also have the rash on my hips and it is the worst in my stretch marks on my hips. The rash is red and bumpy in my stretch marks. I didn’t get any stretch marks in pregnancy so these are old from when I was a teenager. I know PUPPS usually starts in stretch marks but I didn’t think it was common postpartum. No changes to any soap, lotion, detergent.

Just wondering if anyone has experienced something similar. So itchy! Making a doctors appointment today!