Crusty ears

Re: Crusty ears

Bob Russell — Thu, 02 Jun 2011 10:27:41 GMT

[quote user="Stephen Courtney"]

I have seen several cats this late spring with red irritated crusty ears due to a reaction the sunscreen that i recommended. Not best pleased, suspect in cats the issue is PABA (para amino benzoic acid) which features in most sunscreens. Any skin cream can cause a skin flare - if you read the instructions they always recommend test patching in an unobtrusive area. Or is that carpets..?

Solar dermatosis takes years to develop, and, so sorry, we have NOT had that sunny and hot a springtime!

[/quote]

Sunburn can happen in a few minutes if the UV levels are high enough as I found to my cost on holiday. I have seen UV warnings on the weather forecast (UK) in February so sunburn cannot be ruled out however I would agree it is not top of the dd list. Suncream reactions are more likely, I suspect they have been tested on rabbits and humans more than dogs or cats.

Re: Crusty ears

Julian Earl — Wed, 01 Jun 2011 21:58:19 GMT

Just echoing Steve above. I saw a labrador with the same sort of thing a couple of months ago. I was considering all the usual suspects like ringworm, mange, vasculitis etc., but opted for antibiotics while I waited for dermatophyte culture. Whaddya know, three weeks of clindamycin and it was gone. So, no I can't offer a diagnosis either.

Re: Crusty ears

Stephen Courtney — Wed, 01 Jun 2011 21:19:44 GMT

For what it's worth, I have actually seen a dog with ears exactly like the one in the picture. i decided best approach was a long course on antibiotics while waiting to see what happened next. Spent plenty of time discussing this with the client - not willing to spend anything on tests.

Never saw the dog again, suspect they went down the road for steroids. That, or I cured it.

Re: Crusty ears

Stephen Courtney — Wed, 01 Jun 2011 21:15:14 GMT

Solar dermatosis takes years to develop, and, so sorry, we have NOT had that sunny and hot a springtime!

Re: Crusty ears

Stuart Fitzgerald — Wed, 01 Jun 2011 12:07:00 GMT

No culture done as yet Richard but I'll get on it as well as taking a couple of biopsies. No history of foreign travel.

Re: Crusty ears

Richard Fox — Tue, 31 May 2011 16:50:51 GMT

I would approach this systematically. Scrape and smear to look for pathogens (inc cytology) - response to antibiotics and if all negative then biopsy :) JRT's do get ischemic dermatoses at this site so the crusting could lead to alopecia - a bx would be diagnostic for this. No evidence of ringworm?

Re: Crusty ears

CatherineThomas — Tue, 31 May 2011 16:15:05 GMT

Has the dog ever been abroad? I had a dog with suspected leishmaniasis and he had similar lesions on his ears and then went on to develop other symptoms.

Re: Crusty ears

James Laidlaw — Tue, 31 May 2011 16:12:39 GMT

It's not a reaction to the suncream is it?

Can you get sunburn in the UK?

Re: Crusty ears

Stuart Fitzgerald — Tue, 31 May 2011 16:01:47 GMT

Sorry- forgot to mention the owner was advised to apply sunscreen to the ears some weeks ago. He doesn't describe her as a sunbather when questioned but it is a non-pigmented area so I would consider sunburn a possibility.

Regarding the possibility of sarcoptic mange I would expect that we could exclude it at this point given she has had three treatments with stronghold at an appropriate dose. I would normally use it at intervals of two weeks for treatment of sarcoptes but Pfizer assure me that using it every four weeks is adequate.

A pemphigoid-type process did spring to mind and my first impulse was to biopsy so I will suggest this to the owner. Thanks to everyone for the advice.

Re: Crusty ears

Bob Russell — Tue, 31 May 2011 15:44:02 GMT

Just a thought - is the dog a sunbather? Not sure I would recognise sunburn on the pinna but perhaps should at least make it to the differentials list!

Re: Crusty ears

Anthony Todd — Tue, 31 May 2011 15:22:23 GMT

[quote user="Stephen Courtney"]I'de expect sarcoptes to be very itchy from the start.[/quote]

Er, so would I so I take my erroneous diagnosis back, except that I've never seen one after prolonged steroids.Teach me not to absorb the obvious clue in the history.

I'd still use Eurax topically, would dissolve the scabs and kill any residual mites too.

Re: Crusty ears

Stephen Courtney — Tue, 31 May 2011 14:17:00 GMT

I'd be keen to biopsy to rule out immune mediated pemphigoid type issues. I'de expect sarcoptes to be very itchy from the start. could be other mites like cheyletiella but they usually show up easily on scrapes. might be worth repeating scrapes, also try a tape strip, and if you have one of those dermafyte culture thingies, that would be a good idea.

Given irregular ear margins I'd suspect this has been grumbling away for some time, poss vasculitits affecting the pinna margins?

Biopsies can be frustrating though - a lot of effort for a description rather than a diagnosis, so aim for good samples at the margins of normal and abnormal tissue and take as many as practical. And warn client that while it might not provide a diagnosis, exclusions can be very useful too!

Re: Crusty ears

Bob Russell — Tue, 31 May 2011 13:22:19 GMT

Sarcoptic mange should be itchy but this may be masked by the steroids. I have found stronghold a lot more effective for diagnosis than skin scrapings but this is probably more down to my sampling technique. I agree this looks fairly classic. Biopsy it?

Hate to say it but I do use short acting steroids in cases of probable fox mange (naughty I know) but the first days after treatment can be quite distressing for the dog. If it doesn't get better or improves then deteriorates I start to investigate. The dermatologists out there are probably going puce at this approach so crack out the diazepam if necessary!

Re: Crusty ears

Anthony Todd — Tue, 31 May 2011 12:53:49 GMT

Far be it for a dinosaur to comment, let alone diagnose, but it looks like classic scabies to me.

Give away used to be mild lesions on the inner forearms of family members, or the midriff, where they pick up the dog. and/or mild lesions developing on the inside of said dog's forelegs too.

Scrapings are positive in 10% of cases only, someone opined once.

Eurax, Crotinonium [spelling?] in lotion or ointment ,has profound anti-itch properties and is scabicidal and used to be very successful when massaged into the area daily with forefinger and thumb.

Suspect steroids would have made it worse, and I'm a steroid disciple.....