Feline allergic skin disease medications

RE: Feline allergic skin disease medications

Judith Joyce — Thu, 12 Jan 2023 20:21:09 GMT

Sounds good - good luck

RE: Feline allergic skin disease medications

Kate Richardson — Thu, 12 Jan 2023 09:07:59 GMT

Update- saw her this morning- all healed and hair fully regrown! Hasn't had Atopica since before Xmas as people looking after her couldn't administer it, so solely has depomedrone on board. Thus I suspect compliance was the issue!! Is eating z/d happily now, so plan to transition to 100% z/d, cont depomedrone for another 3 months, then if all still good, will stop the steroids and see what happens with diet alone.....

RE: Feline allergic skin disease medications

Kate Richardson — Wed, 11 Jan 2023 15:30:22 GMT

Thanks Judith

Full histo report below (not sure why I didn't post it all the first time!)

When it first started (left side of neck) we thought it might have been triggered by a sore tooth, so I extracted the tooth and did an excision biopsy at the same time, fully excised the visible lesion. However, she continued to traumatise the area. Started pred 5mg bid and she stayed on that dose for approx 4 weeks before it healed, (she weights 3.5kg) but she then started scratching the other side! despite being on 5mg pred bid still. At that point we started a hypoallergenic diet and elected to wean off the pred and started cyclosporin. However for some reason, the Owners didn't collect the cyclosporin and they continued 5mg pred bid for another month- the lesions had resolved and hair was regrowing but she was still prone to scratching the area. So we did start cyclosporin at that stage alongside the pred initially but weaning the pred down and another month later we were down to 2.5mg every other day and cyclosporin daily and everything was looking great! Reduced the pred further and weaned off it, and reduced the cyclosporin to every other day and everything seemed under control.

Fast forward about 3 months, lesions recurred bilaterally when Os ran out of cyclosporin. Diet wise they hadn't continued with the HA diet.

Restarted cyclosporin and added in pred 5mg sid as initially the pruritus wasn't settling on cyclo alone. Continued on these doses for 2 months as things were slowly improving and restarted the HA diet but another 3 weeks later and there was no further improvement. Antibiotics given at this stage (Convenia- cat was becoming more difficult to medicate and wouldn't eat the HA diet with the meds on) - no improvement.

Depomedrone given to cover over the Christmas period as Os were going away, and adv cont cyclosporin, and changed to z/d for diet.

Am awaiting an update from owners!!

Macroscopic Description:
Skin.
A beige brown irregular wedge of skin measuring 21x15x3mm with a portion of
mass measuring 10x8mm. Margins are inked on receipt of tissue. Cruciate
sections are taken.

Microscopic Description:
Skin, ventral neck (3 sections). There is locally extensive ulceration in the
submitted sample of haired skin with superficial necrosis. There is prominent
exudate accumulation and crust formation at the surface of the skin in this
area. The crust contains numerous degenerate granulocytes, abundant keratin and
cellular debris and proteinaceous material. Where intact at the margins of the
ulcerated areas the epidermis is markedly and irregularly hyperplastic and
spongiotic but well organised. No inclusion bodies were identified. There are
more intact areas where the overlying epidermis is markedly hyperplastic with
hyperkeratosis and parakeratosis and further crusting. In the ulcerated focus
there is mild to moderate hyperplasia and hypertrophy of endothelial cells and
fibroblasts within the superficial dermis. Extensively in the dermis there are
interstitial to perivascular mild to moderate infiltrates of eosinophils and
these are mixed with small to moderate numbers of neutrophils, lymphocytes and
plasma cells and scattered mast cells. No parasites were identified in the
examined sections.

Histological Diagnosis:
Dermatitis, ulcerative, exudative, hyperplastic, eosinophilic, locally
extensive, chronic, marked, skin of ventral neck.

Comment:
In this sample of skin there is evidence of eosinophil-rich inflammation and
this is associated with extensive ulceration and crust formation. It is likely
that excoriation from pruritus is contributing to the ulceration and
superficial changes which are present. The presence of eosinophils in the
infiltrates suggests the lesion could be part of the spectrum of lesions of the
eosinophilic granuloma complex or eosinophilic plaque. Underlying
hypersensitivity or parasitism are potential triggers. Other factors leading to
self trauma may need to be excluded clinically. No evidence of neoplasia was
identified in these sections.

RE: Feline allergic skin disease medications

Judith Joyce — Wed, 11 Jan 2023 12:43:05 GMT

Hi, I've been watching this over Christmas and thought with a new year, I'd suggest a new start but it will still be frustrating. I wouldn't go looking for other anti-inflammatory drug options until I knew a bit more about the history and possible underlying causes. Apologies if you have already done the investigations and I missed them.

Frequently the case, unfortunately, the histological diagnosis isn't a diagnosis its a microscope level description of what you have said in the first paragraph. ? have another read of the original biopsy report for clues or ask the histopathologist for another look in case a third party has just put their interpretation on the clinical record. So far, evidence of inflammation, probably much of it self trauma are described.

Ectoparasitic treatment as if it is flea bite dermatitis, especially if any other dogs or cats in the house,

investigation of allergy still needed but will be difficult with an uncomfortable cat. Food trial already sounds difficult, is it an indoor cat or is it eating out at the neighbours? Other allergies also need a look for long term control but the lesions need aggressive treatment first.

I'd leave biopsies for now but primary microbial disease isn't ruled out, so ? ask for fungal stains on the sections but that adds cost. Surface smears may help identify microbes.

Is it recurrent or persistent with waxing and waning of lesions? The latter is more likely and courses of treatment which go at least a month beyond clinical cure may be needed, I'd avoid topicals as they may cause irritation and will be groomed off (worth checking what the client is doing, years ago, Clients have been known to use additional helpful treatments like Dettol or TCP without letting on. . As prednisolone seemed to work the first time, I would go back to that. High end inflammatory dose with no dose tapering until significant clinical improvement and then monitoring before each dose reduction continuing till at least one month beyond clinical cure.

Two provisos - no contraindications to prednisolone which means includes for microbes before starting unless the client really can't do that. The client needs to know it may very well still come back so they should be offered allergy work up as well now.