Silvery skin scales on ear surfaces

Question
My rabbit has an inch patch of these scales across the middle of the outside of her ears, with some also along the lower half on the undersides.  No smell/nothing at all in the ear canal, beyond usual occasional little bit of wax (I clean them as she can't, arthritis).
The vet prescribed three ivermectin injections at 2 weekly intervals, and twice-daily Fuciderm gel.  It's now a week later, with no lessening of the scales, though the constant troublesome itchiness has gone.  (I've now stopped the gel as instructions advise after 3-5 days).
A fellow etherbunner's got exactly the same rabbit problem - itchy/scaly ear surfaces, no other symptons - we and the vets are stumped.  Have you come across this?  Maybe in time the ivermectin will get rid of the cause and ths skin heal (and as the other etherbunner isn't using it, that would be 'proof', if her rabbit doesn't improve).  Thank you.

Answer
Dear Dinah,

Yes, I've seen this.  I think it's usually caused by fur mites (Cheyletiella parasitivorax), which is probably why bun isn't itching any more.

Now that the ivermectin has done its job, you might want to get a bit of soft, clean cotton gauze, soak it with chlorhexidene flush (or dilute betadine) and give the scaly areas on her ears a gentle scrubbing to remove the scales.  The bunny may just not have groomed them off yet.

If you can get Revolution (selamectin), that can sometimes provide a more long-lasting solution to this type of problem.

Hope this helps.

Dana