Bumpy Awful RASH HELP

So about a week and a half ago I had two small bumps pop up, it has spread. It’s below my butt cheek line and on the back of my calf. I haven’t been sexually active too recently and not in the timeframe where this happened. I haven’t changed my diet. We switched laundry detergent like three weeks ago but I’m not sure why it’d be isolated to these areas. We have bug bombed the house, washed everything on hot, and I have had two doctors appointments where they have basically said they have no idea. We’re trying to get in with the dermatologist but she’s been on maternity leave. I’ve been using steroid cream and taking an antihistamine and it hasn’t been helping. It itches horribly and seems to be slowly spreading (but idk). The lines are from my blanket, completely unrelated lol.