help!

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so I have a dark brown mark like this on both of my hip bones. i've assumed it was dead skin and have actually gotten some dead skin off but they're both still there, and they look like bruises. I always walk into things and lean up against things and I'm wondering if maybe that's what it's from? does anyone have any ideas of how to get rid of it? they never go away and I'm at a loss and I'm low-key insecure about it lmao