Cat's skin around ears gone yellow

Recently tool my 3 year old cat to the vet as she lost a substantial amount of weight over a month or two. She used to be pretty fat, now she's underweight at 3.6kgs. The vet gave her medication as she suspected she had a type of tapeworm (tapeworm from memory). My cat. Would hopefully put weight back on over 2 weeks. Over the past two days I have noticed the skin on her ears and in front of her ears where there's little fur has gone a yellowy tinge. Could this be a effect from her worming medication? What could this be caused from?

Thanks

I attached a image using flash which does highly exaggerate the tone of yellow

Here is a pic without the flash. She had the medication about a week ago. I believe she's eating ok - its hard to keep track with 3 cats.

I strongly suggest you get your cat to the Vet asap for treating and diagnosis. I have never personally seen or heard of a cat's fur around the ears turning yellow(ish) before, but the fact that she has previously lost weight and was treated for worms because the Vet 'suspected' worms (did the Vet not do a stool specimen to confirm his suspicion? - it's a 30 minute/$10 test). 

There are a couple things that bring other questions to mind... 

How is your cat eating?

What type of diet is she on? Wet - Dry - or a combination?
How is your cat drinking? (they need plenty of fresh water!
Is she properly hydrated? You can check this a couple ways - 1.) lifting her scruff and seeing if it returns rapidly or if it tents and goes back slowly. 2.) Gently pressing your finger pad on her gums - are they slick and moist? Or dry and slightly sticky? Also, are they pink, or a pale white/grey color? 
What does the rest of her coat look like? Is it shiney and sleek? Or dull and coarse? 
How is her activity level? 
Do you notice any lethargy or abnormal hiding?
Is she alert and perky?
Any unusual or excessive meowing?
How about litter box behavior? Is she using the box or pooping/peeing outside the box? Is she straining or trying to go without results? 
What is the consistency of her stools? Firm 'logs', soft formed, liquid, watery, or do you notice any mucous or blood? 
Is she scratching at her ears? 

Honestly, I imagine it could be one of a hundred different causes from a reaction to the worm medication, ear mites/fungal infection, dermatitis, feline leukemia, anemia secondary to the weight loss and not eating, to myriad other things. Looking at the pictures, the yellowing of her skin brings to mind jaundice, which could indicate liver problems.

If your current vet is reluctant or simply makes a 'speculation', you might want to consider taking to her to another vet for a second opinion who will be willing to do blood work and/or culture the affected area. 

As I said, I have never seen this before, so it could be something common and a good vet would recognize it right away and say, "Oh, yea, she has_______". But, whatever it is, it is a symptom of an underlying cause and she should be seen and evaluated as soon as you can get her in. Cats are sensitive and can decline rapidly. 

Hopefully, someone else will chime in and give their opinions and suggestions.  Please, keep us posted!

Your cat may be jaundiced. Get her to a vet right away.

I agree, not a vet but my guess would also be jaundice. You need bloodwork done, if your vet already didnt --on your kitty to check liver, possibly kidneys. Pretty cat, by the way! Never ever good to lose that much weight. I had a cat with jaundiced ears a few decades ago, he and another cat got liver issues the same time, we now suspect the food but we really aren't sure. Both mostly eventually recovered but did die younger than they should have.

Thanka guys have booked the cat in for the vet tomorrow. I suspect they will do a blood test

Just to reiterate the others, could be jaundice, and you definitely want to get that checked out. Glad you were able to book an appt! 

Well, I'm late finding a thread once again, but now that I have, please, an update?

How did the vet visit go? I hope your kitty is ok

Hey guys,

Turns out she had jaundice because of feline cholangiohepatitis. They thought she may not recover but she's showing great signs. Her toxin level was off the charts - higher than the vet had ever seen. She's eating heaps and has put 300grams on since Tuesday. Thanks a lot for the advice, if I left it another day or two she would have passed away. Thanks!!!

Wow I am so glad you took her in to see a vet. Is it being treated with antibiotics, or immunosuppressants ? Please let us know how she is progressing