Dark Spots Left From Ant Bites

Hello All.  My Donskoy (Sphynx) Dublin is currently 9 months old.  At the age of 4 months, he was attacked by fire ants and this is the result - 5 months later. 

My question is, does anyone know what I can use to "safely" remove or lighten the brown staining left behind?  I plan on showing him in 2017, however I don't think it's a good idea to show him with his skin revealing these speckled marks.  Someone told me the pigment in his skin has caused the staining after the bites.  If that's so, then what can be done to remove it?

Though I've taken him to the vet immediately after the initial ant bites, over the months I've noticed that the spots remained.  Is there something OVER-THE-COUNTER that may be safe to use BEFORE I have his skin tested at the vet's office?

I appreciate all replies

I doubt that there's anything that can easily fix those pigmentation spots. In humans, you have to use lasers to break down the pigmentation or strong chemical to bleach them. I can't imagine a cat being OK with that treatment.
In show terms, how bad are his spots? Personally I think this little speckling is adorable and adds to his charm.

Thank you, Pushylady for your reply.  I was thinking the same thing about the pigmentation and the chemicals doing harm to remove the spots.  That's why I figured I'd ask.  Someone else told me it may be a yeast thing.

I'm afraid a judge won't think it gives him character when he's shown against other beauties with perfect skin.  Maybe I'll post the same question in the threads for "Showing" cats.  Hopefully, it will put my mind at ease regarding how a judge may look at it. 

Thank you again

Hi, it's me again, months later.  Since I've last posted, Dublin's spots have darkened AND SPREAD dramatically!  That's when it was time for me to make it to a vet.  Turns out it was a yeast infection that was remedied with Malaseb shampoo.  He's as good as new.

Now, there appears to be white bumps located at pressure points under his tail and haunches (behind his hind legs).  The vet told me they will eventually turn into calluses.  She just winged it and didn't bother doing a skin scrape or anything...!!  I will definitely get a second opinion.  I didn't want to put out extra $$, but I don't want to wait too long like I did with the yeast infection,  The white bumps aren't oozing anything....yet.  They look more like pimples which aren't ready to be popped

I thought of showing Dublin at one time, but have since changed my mind.  There are too many skin issues which arise unexpectedly and I'd hate to have it happen to me the night before a show.  It would be too nerve-racking for me to deal with that as someone who shows cats.

....OOoops!  Some VERY GOOD buddies from Instagram told me about the Malaseb shampoo before I spent $$ at the vet.  The dark spots disappeared on Dublin's belly within a month of bathing him every 5 days.

I decided after the spots had gone away to take him to the vet for the white spots, since THEY haven't shown any sign of change since using the shampoo, so I knew it had to be something else.  We'll see what it could be, NOW!  Whew!