cat losing hair on outside of ears?

[WeAppearToBeAlright]

Any suggestions anyone?

Happened last year for the first time mid-Summer - she started losing hair from the base of the ear (back of the ear) gradually upwards. Stopped in Autumn, grew back, and just started losing hair again these last few weeks.

I've tried the vet, who basically didn't know. I'm guessing she's picking up some bitey creature from the grass in warmer weather, but how to stop it?! The usual flea/tick stuff doesn't have any effect. She isn't itchy and doesn't appear to notice, although sometimes I can see the odd scab which might be her having a go, or the remains of the hypothetical bitey thing having bitten. And why just the ears?

Any help gratefully received for the poor thing. (not that she seems to know...)

Interestingly, one of my twelve week old kittens has exactly what you describe. The vet noticed it at his first health check but didn't know what it was or seem concerned. The kitten, like yours, isn't at all bothered by it and of course they haven't been let outside yet so his, at least, couldn't be caused by mites.
Sorry, no wisdom to offer! Just an interesting similarity.

If your cat has lost hair on their ears, you need to use sun screen as they are actually quite prone to skin cancer - that is, if we ever get any bloody sun!

Ah, not the only one then. And bitey things probably ruled out, due to lack of itchiness, no obvious bites, and an indoor kitten getting same. Which also rules out most outside factors.

It's only last year and this that she's been affected - her brother isn't losing anything! I wonder if it's a stress reaction that he displays in different ways (he's pooed on the floor a bit recently)? I've had quite a few strangers in and out of the house the last five weeks and they do hate that. So maybe the Summer thing is a red herring and there was a period of stress around this time last year as well... can't remember. Is your kitten a bit stressed at the moment, Juliet?

Thanks for the tip, LEM - how do you stop them cleaning it off?