Hi, I Have A Large Bruise Like Mark On My

Hi, I have a large bruise like mark on my inner thigh that won't go away. It is more red than blue. It shows more when I am in the bath with hot water. It fades as my body cools, but is still barely visible. I've had it for about 5 months. I have mixed connective tissue disease MCTD, which includes Rheumatoid arthritis, lupus & sjogrens. I know that my blood tests show anemia, but my rheumatologist told me that taking iron won't help & that it is caused from my autoimmune diseases. Do you know what would be causing it & how ban I make it go away?