Strange bald spot with lump on hind leg

Hi all- I currently noticed a weird spot on my cat Boots' hind leg last night. I was actually taking a photo of his feet (because they're so darn cute) and upon looking at the photo, I noticed the spot. When I examined it, I saw that it looks bald around it (bald spot maybe the size of a quarter) with a small pinkish area that somewhat looks like scar tissue, with the skin around that area slightly purple. It does not feel fluid filled or raised. We have no clue what it could be, and will be taking him to the vet soon, but I'm wondering if anyone else has ever seen this.

He is up to date on all shots and has not recently had any vaccinations that would cause this. He does play with our other cat occasionally, but not rough that I know of. Never had any dermatitis or allergy issues. I recently lost a cat to heart failure, so the smallest thing makes me so nervous with my kitties now. Any replies are appreciated, thanks.

Update, we shaved it and here are the pics:

I'm no help but I know what it's like to try to recover from a heart failure problem in a kitty (ours passed a year and a bit ago). Every little thing makes you worry. I hope this is just something insignificant like recovering from an insect bite or something. Let us know how you get on!

Yes, I'm curious too.  I was thinking a possible bug bite as well, but seems like there is bruising as well.  I guess it's possible...dont' know what ELSE it could be

Thank you so much, Tobilei. I appreciate it! 

Unfortunately it seems like it might be more serious than we thought. We brought Boots in to the vet and got an antibiotic injection, thinking it was just a skin infection- we saw another spot like it upon examination so this seemed likely. However a few days later, we noticed his paw pads were VERY peely with cracked, dry skin He was also licking like crazy, so we put an e-collar on. We brought him back in, and right now the likely diagnoses are either pillowfoot or pemphigus. He has a sedated biopsy next week to try and figure it out. He is on a very low dose of prednisolone til then, to see if it helps. He is still quite itchy and licks his paws the second you take his cone off, so we have to leave it on. I am also giving him fish oil, and looking into some herbals.

We are really hoping that it isn't pemphigus, since being an autoimmune disorder he will likely need steroids his entire life I know these have bad side effects. It seems like we are having very bad luck right now. At first we thought the spots might be stress related since we just rescued a cat (a friend works at a hospital where he was brought in with a broken leg- family was going to euthanize, so she offered to take him and they surrendered. I later agreed to take him from her). Because he just had orthopedic surgery with a plate, wires, and screws, he absolutely needs to be crated and is really unhappy about it. Add to the equation that he's a Siamese, and you've got a recipe for very loud, very frequent yowling. I thought this could have just stressed Boots out and caused him to start licking and making hot stops. But now it seems it may be autoimmune related.

We are keeping our fingers crossed that it isn't pemphigus. I don't know a lot about the prognosis right now. I've read it's typically good, but that it can be life-threatening in some cats. The good news is he really only has the paw issues right now (which are actually recovering since he can't lick)- he doesn't have any of the face, ear, etc. spots that you typically see with pemphigus. I will be happy when we get a diagnosis for Boots. I have several exams and projects approaching with the end of this semester, so much so that I had to quit my job to try and make more time for all the schoolwork. All these extra finances aren't helping, lol! I keep telling myself that in a month or so, I will probably be able to breathe easier and look back at this differently.

Whew- long winded post!! Thanks for reading it all! 

Wow, who would have thought it was either of those?

Well, in case you need some "light" reading, here's a thread on pillow foot with some links in it:  http://www.thecatsite.com/t/294235/plasma-cell-pododermatitis

Thanks mrsgreenjeens!

Well, our little Boots was supposed to have a biopsy tomorrow morning. He had been put on steroids to see if they helped his paws, which they seemed to help a bit. However last night I noticed him acting a bit lethargic and brought him in. He checked out fine, but the doctor said to keep an eye on him in case he was developing a respiratory infection due to the steroids weakening his immune system. She also said to discontinued them just tin case, since his biopsy was soon anyway. This morning we awoke to a very stuffy, unhappy Boots I've since picked up some antibiotics for him. Anyone know of any other remedies to help soothe him until it clears up? I feel like I've read that running the hot shower and letting steam build up in the bathroom can be good for them when they've got colds.

Yes, the steamy bathroom is good if they're congested, and warming their food so they can better smell it if they don't seem to want to eat.  Plus keep him nice and warm.   Other than that, and antibiotics if necessary, is all I can think of.