If it looks like a bruise, then it probably goes deeper then skin only.
This is general advice, and should be treated as such, but providing the ailment is superficial (i.e., a skin problem only) a friend of mine who is now a G.P. once told me that 95% of skin problems can be completely healed with Vitamin E.
I had an embarrassing patch of dermatitis 'somewhere' and I used a cream with lots of vitimin E and it got rid of it after a week.
Now if ever there's a problem with my skin; anything that looks like Eczema, dryness, dermatitis, rashes, feet weirdness, whatever I first use Vitimin E.