9/2/2016
The Pruritic Cat—Help!!
Let’s work thru the DDx
Or…what to do with the
DepoMedrol stops working!!
Alice Jeromin RPh DVM
DACVD
Feline Atopy
Feline Atopy
“Atopy” is Latin for “strange”.
An inherited exaggerated IgE response to
inhaled or possibly percutaneously
absorbed allergen.
Imbalance of Th-l/Th-2 cells?
Release of inflammatory mediators.
Histamine, leukotrienes, prostaglandins.
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Does feline atopy exist?
Feline IgE has not been isolated,
however…
Reaginic Ab via PCA exists in healthy cats
injected with serum from atopics.
MW of reaginic Ab similar to IgE in other
species.
Feline “IgE” cross reacts with canine IgE.
Feline Atopy-incidence
Studies at Cornell & Univ. of Ga. Found
15%/17% of cats to be atopic (l3%/l5%
found to be food allergic).
FAD most common feline allergy but
atopy just as common as food allergy.
Approximately 3% of cats are food AND
inhalant allergic.
Feline Atopy
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Feline Atopy
Feline Atopy
Feline Atopy-cytology
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Feline Atopy-Causes
Environmental
Vaccinations
Infections
Defective skin barrier function
All of the above have been hypothesized
to play a role in establishing atopy in the
cat.
Feline Atopy-Causes
Atopic cats have elevated CD4+ Tlymphocytes in lesional skin which
supports the role of TH-2 lymphocytemediated immunity in feline atopy (similar
to dogs and humans).
Human vs. Feline Atopy
Genetic-possibly--as commonly seen in
orange colored cats in my practice!
Respiratory vs. dermatologic
Prognosis
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Feline Atopy-clinical info
Age of onset: 6 months-l4 years of age.
Variable compared to dogs or humans.
May start at an older age, unlike dogs.
Seasonal vs. nonseasonal history.
Breeds affected: no breed or sex
predilection--possibly more common in
Devon Rex and “orange” colored catsorange tabby’s, tortie’s, calico’s.
Feline Atopy-clinical signs
Feline Atopy-clinical signsextremely variable!
Self-induced alopecia-truncal, abdominal,
legs, face
Miliary dermatitis, plasma cell
pododermatitis
Eosinophilic granuloma complex--rodent
ulcer, eosinophilic plaque/granuloma
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Feline Atopy-presentations
Feline Atopy-presentations
Feline Atopy-presentations
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Feline Atopy-additional
clinical signs
Exfoliative dermatitis
Malassezia otitis, seborrhea, chin acne
Eosinophilia, lymphadenopathy
Asthma-not a normal symptom of feline
atopy, but possible!
Feline Atopy-asthma
Study by Probst of 20 feline asthmatics
treated w/ allergen avoidance (cockroach,
storage mite)—3 improved. 12 treated
with immunotherapy—after 6-9 months,
8/l2 were controlled. 4 cats still required
inhalant rx’s and 2 remained on steroids
and became diabetic.
Feline Atopy-asthma
The most common allergens reported in l
study of asthmatic cats were dust mites
and Bermuda grass.
Cyproheptadine, Cetirzine, Zaferlukast-all
no help in experimental asthma.
Janus Kinase l (JAK-1) inhibitor was
effective in experimental asthma
treatment in cats.
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Feline Atopy
Feline Atopy
Feline Atopy
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Feline Atopy-RULE OUTS
Flea allergy dermatitis
Dermatophytosis
Cheyletiella
Demodex-3 species
Notoedres
Pemphigus foliaceus
Food allergy
Malassezia dermatitis
Flea Allergy Dermatitis
Atopics more prone to Owner’s perception of
FAD.
fleas causing pruritus
can be difficult to
Chronic, low grade
overcome.
flea problem can be
mistaken for atopy.
Comb all patients!
Suspect in cats that
Skin or blood test for
are indoor/outdoor.
flea allergy.
Flea Allergy Dermatitis
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Flea Allergy DermatitisTreatment
Advantage, Revolution, or Frontline
Topspot q 2 wks x 2 doses, then monthly
and/or Capstar once weekly, Comfortis q
3-4 weeks, or Seresto collar. Treat for 3
mos straight!
Treat ALL the pets in the house.
Treat the environment using an adulticide
and an insect growth regulator (IGR).
Cheyletiella (“Walking
Dandruff”)
Can be difficult to find as cats are good
groomers.
Flaky, dandruffy along dorsal trunk-most
common presentation.
Eosinophilic granuloma complex.
Miliary dermatitis.
Recurrent sneezing, facial pruritus.
Patient may be DepoMedrol responsive.
Cheyletiella-Diagnosis
Combings, skin scrapings, Scotch tape
technique, fecal analysis, skin biopsy.
Large mite, eggs and larvae resemble
hookworm eggs.
Comb all pets-asymptomatic carriers exist!
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Cheyletiella-Treatment
Weekly pyrethrin bath x 4 wks.
Lime sulfur dips weekly x 4 wks.
Frontline Spray q 3 wks x 2 applications.
Revolution q 2 wks x 3 doses.
Ivermectin 200ug/kg/wk x 3 wks.
Advantage Multi q 2 wks.
TREAT THE ENVIRONMENT and all pets in
contact with the patient!
Cheyletiella Mites
May have
aysmptomatic
carriers—check all
pets in the
household.
May affect elderly
pets or those with
underlying internal
medicine problems.
Suspect in allergic
Cheyletiella mites
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Cheyletiella mites
Cheyletiella mites-hard to
find!
Notoedres-Feline Scabies
Rare--regional “pockets” of infestations
exist across the country.
Crusting, pruritus of head/ears/hocks.
Mite easier to find than canine scabies
mite.
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Notoedres-Feline Scabies
Notoedres-Treatment
Lime sulfur dips weekly x 4 wks.
Ivermectin 200ug/kg/wk x 3 wks.
Revolution q 2 wks x 3 doses.
Frontline Spray q 3 wks x 2 doses
Advantage Multi q 2 wks
Treat the environment and any other
exposed cats.
Food Allergy
Nonseasonal, may be somewhat steroid
responsive.
Affects any age patient.
Any area of the body can be affected,
sometimes just head and neck.
Consider in recurrent yeast otitis.
Must use prescription hypoallergenic diet.
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Food Allergy
Food Allergy-Diagnosis
There is no valid blood or skin test to test
for food allergy!!
HYPOALLERGENIC DIET TRIAL FOR 4-6
WKS. Canned vs. dry
Hypoallergenic diet: a diet without any
ingredients to which the patient has been
previously exposed. No OTC “limited
ingredient diets” or “grain free” diets!
There are other ingredients in those foods
not listed on the label!
Food Allergy-Diagnosis
Must eliminate corn, wheat, egg, beef,
chicken, soy, dairy, fish, and lamb, if
eaten previously.
Choices include: Iams lamb/barley,Hill’s or
Royal Canin venison/duck/rabbit/lamb &
pea diets, Hill’s Z/D or protein hydrolysate
diets, Blue Buffalo HF.
Home cooked diets
Taurine deficiency, malabsorption.
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Food Allergy-interesting
stuff!
Gi parasites in young cats may lead to
eventual food allergy.
Experimentally infected cats with
Toxocara canis followed by feeding
human serum albumin supported a role
for T. canis enhancing IgE response to
orally administered albumin.
Dermatophytosis“Ringworm”
Always consider in Persian cats & shelter
cats!
Wood’s light: allow to warm up for l0-15
minutes, only 5 species fluoresce positive,
looking for apple-green color.
Culture: MacKenzie toothbrush technique,
send to lab for positive identification.
Trichogram, PCR for dermatophytes
Skin biopsy with PAS stains if necessary.
Dermatophytosis
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Dermatophytosistrichogram
Dermatophytosis-fungal
culture (DTM)
Dermatophytosis-positive
Microsporum gypseum
Always send the
fungal culture to the
lab for confirmation
of dermatophytes vs.
contaminants!
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Dermatophytosis-clinical
Pruritus head/neck in some patients.
Alopecia, crusting, scaling but can be
EXTREMELY VARIABLE in appearance.
Steroids may initially squelch the
associated inflammation.
Zoonosis
May need to allow culture to incubate for
up to 4 weeks--new findings.
DermatophytosisTreatment
Topicals: lime sulfur, chlorhexidine,
miconazole, clotrimazole
Fulvicin U/F 30mg/lb/day divided with a
fatty meal. Watch for pancytopenia, FIV
negative before using.
Itraconazole 5mg/kg/day sid x l wk, off l
wk and repeat x 3 courses. Do not
compound!
Fluconazole 50mg/cat x l5 days & recheck
Dermatophytosis-feline,
Treatment
Moriello, Coyner, Vet Derm 24, 2013
Terbinafine x 21 days with 2x/wk lime
sulfur dip as effective as Itraconazole.
Terbinafine dose: 250mg tablet-1/4th
tablet sid if cat <2.8kg, l/2 tablet sid if
2.8-5kg, l tablet sid .if >5kg
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Feline Demodex-3 species
DEMODEX CATI-appearance much like
Demodex canis (long, slim body).
LOCALIZED-patchy crusting, scaling,
erythema, alopecia. Head and/or neck.
May present as a ceruminous otitis.
Rx: lime sulfur, amitraz in mineral oil-lcc
in 29cc mineral oil-make up fresh weekly,
Tresaderm, Milbemite. May be selflimiting.
Demodex cati-generalized
More common in purebred cats-Siamese,
Burmese.
Head, neck, trunk, limbs-alopecia,
crusting, scaling, redness.
CHECK FOR UNDERLYING DISEASE-I.e.
FIV, FeLV, SLE, feline Cushing’s disease.
Demodex cati-Treatment
Treat the underlying disease, if possible.
Lime sulfur dips every 5-7 days, carbaryl
shampoos, amitraz dips at reduced
concentrations (amitraz not approved for
cats).
Ivermectin 200ug/kg sid has been usednot approved, deaths reported.
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Demodex cati
Demodex cati
Demodex cati
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Demodex gatoi
Formerly unnamed demodex species.
Short, broad, blunted body
Even a few mites can cause pruritus—
hypersensitivity reaction to mites.
May not be to find on scrapings and/or
combings as lives in top layers of the skin.
Can be found in fecal flotation analysis.
Demodex gatoi-Clinical
Clinical signs similar to allergy or scabies.
Alopecia, pruritus, generalized erythema,
symmetrical alopecia. Crusting, scaling.
May be present in conjunction with
underlying allergy or as a result of
overuse of steroids.
Usually no serious underlying disease.
Demodex gatoi-Treatment
Lime sulfur dips q 4-7 days for 6 wks.
Higher concentration—8oz lime dip/l20oz.
water is recommended. No rinsing.
Ivermectin-200-300mcg/kg orally sid for
up to 6 wks. Careful of neurotoxicosislethargy, ataxia, hypersalivation, tremors,
mydriasis, blindness, bradycardia.
Advantage Multi q 7-14 days (q 7 days x
l0 doses).
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Demodex gatoi-Treatment
Doramectin (Dectomax injectable, Zoetis)
600mcg/kg SQ weekly. Adverse effects
similar to Ivermectin.
Bravecto 25mg/kg orally or spot-on
available in Europe
Highly contagious—treat all cats in
household.
Demodex gatoi
Demodex gatoi
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A 3rd feline demodex mite!
Has been described in cats but yet
unnamed.
Longer body than D. gatoi but shorter and
wider than D. cati.
Seen in association with D. cati and D.
gatoi infestations and underlying illnesses.
D. canis can occasionally be found on
feline skin!
Pemphigus Foliaceus
Multifocal crusting, blistering- face,
pinnae, nailbeds, nipples or just l of these
areas.
Usually febrile.
Steroid responsive-temporarily!
Variable pruritus.
Pemphigus FoliaceusDiagnosis
Diagnosis is by cytology and/or skin
biopsy.
Biopsy of a pustule or crust shows
acantholytic cells in superficial layers of
the skin.
CBC-may see neutrophilia or eosinophilia.
Cytology-degenerative neutrophils,
eosinophils with acantholytic cells.
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Pemphigus foliaceus
Pemphigus foliaceus
Pemphigus foliaceus
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Pemphigus foliaceusTreatment
Prednisolone (not prednisone) l-2mg/lb
sid until in remission then taper dosemonitor for diabetes!
+/-Leukeran 2mg qod-monitor cbc’s--$$
+/-Doxycycline 5mg/kg/day-use solution
but if compounded-only stable for l wk!
Sun avoidance
Malassezia
dermatitis/otitis
Not as common as in dogs.
Can affect skin folds such as facial folds,
ears, groin.
Pruritic
Generalized Malassezia-look for
underlying FIV infection
Sphinx, Devon Rx breeds prone?
Malassezia dermatitisDiagnosis
Skin cytology-especially chin smears
Ear smears-check for yeast, bacteria and
do smears in oil for mites
Fungal culture-add oil to culture medium
Skin biopsies-superficial perivascular
dermatitis, yeast may be washed off in
slide preparation
May accompany allergy
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Malassezia dermatitis
Malassezia
otitis/dermatitis
Malassezia spread by
cat grooming from
the ears across the
face and down to the
chin.
Yeast hypersensitivity
Malassezia
dermatitis/otitis
Check ear smears for
yeast.
Check face/chin
smears for yeast.
Ketoconazole 200mg
l/8th sid or qod
Miconazole/synotic
ear drops 1-2 AU sid.
NO EAR FLUSH
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Malassezia
dermatitis/otitis
May also see staining
or licking of the
medial aspects of the
front legs from where
rubbing ears onto
face with legs.
Malassezia dermatitisTreatment
Ketoconazole 2.5mg/kg daily with foodwatch for vomiting/anorexia OR
Fluconazole 50mg once daily.
Sporanox 5mg/kg/day-less gi side effects,
watch for liver enzyme elevation. May
“pulse dose” once under control.
Topicals such as Malaseb shampoo but
difficult in the cat! NO TAR OR HEAD &
SHOULDERS SHAMPOOS IN THE CAT!!
Feline Atopy-A diagnosis of
exclusion!
Must rule out the previous diseases first.
Treat any ectoparasite infestation first.
Once you have ruled out flea allergy, food
allergy, as well as the other differentials
you are ready to pursue a workup for
feline atopy…
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Feline Atopy-Diagnosis
What time of the year is the cat affected?
Nonseasonal-dust mite--most common
allergen in the cat, dog & man; molds
(rare)
Spring-trees pollinate in March, April
Summer-grasses
Fall-weeds, eg. Ragweed is mid-August
through mid-October
Feline Atopy-Diagnosis
Whichever test you decide to do i.e.. Skin
or blood testing--THE POSITIVES NEED
TO CONCUR WITH THE TIME OF THE
YEAR THE CAT IS AFFECTED!!
Feline Atopy-Skin testing
Do not reuse testing needles because of
FIV, FELV, FIP transmission.
Study of 28 atopic cats: 50% positive to
dust mite, 48% positive to dust mite and
pollens. Immunotherapy effective in 73%.
Steroid, antihistamine, megestrol
withdrawal times.
Anesthesia.
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Feline Atopy-invitro testing
Measures antigen-specific feline “IgE”.
Biomedical Labs, Greer-ELISA
Spectrum-RAST
VARL-EIA correlating with Western blot
Heska-Fc-receptor technology
University of Penn.-Polyclonal ELISA
RESULTS MUST MATCH CLINICAL
HISTORY!!
Feline AtopyImmunotherapy- Injectable
Can take l-4 mos, sometimes up to l yr.
Success rate 60-75% based on
intradermal skin testing.
Monthly injections rarely control.
Monitor closely for adverse reactions:
dyspnea, vomiting, diarrhea, inc pruritus.
Keep l2 or less allergens/vial. Do not mix
grasses with molds in the same vial.
Immunotherapy-Injectable
If after lyr you are not seeing results-Are too many allergens in the solution?
Is the solution strong enough…or too
strong?
Shorten the interval between injections?
Does test correlate with patient history?
Is the diagnosis of atopy correct?
Are ectoparasites new on the scene?
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Immunotherapy
What about hyposensitization without
allergy testing?
DOGS on hyposensitization based on idst
vs. not tested (treated with regional mix
of allergens) showed a 70% improvement
after 8 mos. Non-tested dogs improved
only 20% (same as placebo). No current
data for cats on this issue.
Inhalant allergy –
Sublingual Immunotherapy
Sublingual immunotherapySLIT
Involves absorption
of allergens through
the oral mucosa.
Uptake and
processing by
specialized dendritic
cells.
Special formulation
allows for allergen to
be stabilized and
absorbed across MM.
Primarily indicated for
dogs, results in cats
and horses not yet
reported.
Not evaluated for flea
or food allergies.
Used in humans for
food allergies.
Skin or serum test to
determine allergen
content of solution.
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Feline Atopy-TreatmentFatty Acids
Fatty acids- Make “good” prostaglandins
that compete for more inflammatory
“bad” prostaglandins.
50mg/kg daily combined DHA/EPA via
capsule or liquid
Side effects: vomiting, anorexia, diarrhea
Feline Atopy-Treatment-Antihistamines
Hydroxyzine lmg/lb bid
Chlorpheniramine 4mg l/2 tablet s-bid
Amitriptyline 0.5-lmg/kg sid
Clemastine 1.34mg l/2 tablet bid
Loratadine l0mg/cat sid
Cetirizine (Zyrtec) 2.5mg/cat sid
Montelukast (Singulair) .25-.5mg/kg sid
Feline Atopyantihistamines
Few clinical studies showing efficacyimprovement of pruritus in atopic cats:
50% improved on Clemastine
45% improved with Cyproheptadine
77% improved with Chlorpheniramine
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Antihistamines-continued
Cetirizine 5mg/cat sid
controlled pruritus in
41% of cats w/
allergic skin disease.
Griffin JS, Can Vet J,
2012.
Cardiotoxicity in
humans using
terfenadine-not
detected in dogs or
cats using loratadine,
terfenadine, or
fexofenadine.
Feline Atopy-Treatment
Antihistamines, con’t:
Side effects-drowsiness, hyperexcitability,
teratogenicity, hypersalivation due to
bitter taste
Cetirizine (JAVMA May l5, 2008) lmg/kg
sid tolerated well, highly protein bound in
cats.
Study in Vet Derm 24, 2013—Cetirizine
not effective!
Feline Atopy-Treatment
STEROIDS
Use if symptoms<3mos/year
DepoMedrol usually more effective than
oral steroids...but overuse can produce
diabetes, cardiomyopathy. Caution in
elderly cats especially!
Prednisone vs. Prednisolone in the cat.
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Feline atopy-steroids, con’t
More likely to cause diabetes or heart
disease w/ repeated long-acting steroid
injections-especially geriatric cats.
Some atopic cats can be controlled with
prednisolone 2-3x/wk or prednisolone
with cyclosporine on alternate days.
Dexamethasone 1-2x/wk orally also
possible-long-acting so avoid sid. If
controlling w/ steroids check glucose q6
mos.
Feline Atopy-Treatment
MEGESTROL ACETATE-OVABAN
Not advised due to side effects including
diabetes, mammary hyperplasia/neoplasia
Safer alternatives available.
Feline Atopy-Treatment
Cyclosporine-Atopica, Neoral, generics
DO NOT COMPOUND-you’ll see why later!
Renal transplant doses: 5-30mg/kg
Neoral oral liquid l00mg/ml--available in
50ml bottles-must use within 60 days of
opening bottle. Atopica for cats 5ml &
l7ml bottles (l00mg/ml).
Atopy dose: 2.5-5mg/kg/day, new study
using 7mg/kg
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Feline Atopy-Treatment
King S, et.al Vet Derm 23, 2012Cyclosporine 7mg/kg sid in atopic cats for
6 wks found to be effective and well
tolerated.
9-l5% lack of response or inadequate
response
Reduction in wbc but still in normal range
at 20mg/kg sid dose.
Feline Atopy-Treatment
Vet Derm 2013, Steffan J, et al.—7mg/kg
sid x 30 days then taper to qod for several
weeks. If in remission- go to 2x/wk. Up to
57% of patients could be tapered to
2x/wk.
First study of tapering cyclosporine dose
in cats.
Feline Atopy-Cyclosporine
Side effects: vomiting, diarrhea,wt loss,
anorexia,lethargy,hypersalivation
Bioavailability varies in cats.
Advantage over steroids-not diabetogenic,
doesn’t cause muscle atrophy
Alternative to steroid use
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Feline Atopy-Cyclosporine
Lappin MR, Effect of oral administration of
cyclosporine on Toxoplasma gondii
infection status of cats. Am J Vet Res,
2015;76 (4): 351-357.
Cyc. 24mg/kg sid for 56 days in l6 cats, l6
cats on placebo—vaccines given l6wks
prior w/ pretreatment serology confirming
antibody responses. Con’t…
Cyclosporine study, con’t
Antibody titers measured days 7,28, 35,
56. Following booster vaccination, no
differences between FCV & FPV. Titers
adequate for FHV-1, FeLV, rabies.
Cyclosporine summary
Cats on cyc therapy likely to receive
protection from boosters. Initiating NEW
vaccines may not lead to protection.
Toxo-naïve cats not exposed started on
cyc, may experience clinical disease. Cats
on cyc therapy rarely experience severe
clinical toxoplasmosis.
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Feline Atopy-Cyclosporine
Not advisable to use in outdoor cats
exposed to raw meat.
We routinely check cbc/profile/urinalyses
while on cyclosporine--3 patients
developed neutropenia which was dose
related.
Monitor weight while treating,check gums.
Anorexia may signal toxicity.
Compounding cyclosporineDON’T!
Umstead ME, et. al. Accuracy and
precision of compounded ciclosporin
capsules and solution. Veterinary
Dermatology, Vol. 23, Issue 5, Oct. 2012.
Summary-compounded cyclosporine
solutions may deviate >10% from the
labeled strength.
The bioavailability and clinical efficacy of
compounded cyclosporine remains
unknown.
Compounded cyclosporinecon’t.
Umstead study-continued: Both capsules
and solution were compounded by
pharmacies advertising compounding:
Drug was found leaking from the
capsules. 2 of the solution preparations
had accuracy <66% and 122% higher
than the labeled strength. Only l was a
solution, the rest were suspensions with
visible particles and no “shake well” label.
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9/2/2016
Atopica Liquid-brand name
commercial veterinary
product
Feline Atopy-food storage
mites
Tyrophagus putrescentiae-storage mite
found in cereals, grains, cheese, dry
foods.
Pruritus/excoriation of the
ears/head/neck.
Diagnosed by skin or blood testing.
Treatment by feeding canned diet without
cereals, grains, or cheese.
Feline Atopy-Dust mites
D. farinae, D. pteronyssinus
Most common allergen in dogs, cats,
humans
Darkness, dampness, nonseasonal
Treatment-avoidance, immunotherapy,
environmental control-Acarosan (benzyl
benzoate)-no longer made.
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Feline Atopy-Dust mites
Best for household treatment:
Airing fabrics on hot sunny day or cold dry
day for l2 hours.
Use microporous mattress/pillow covers or
strip off bedding, open windows & allow
airing or wash bedding in hot water or
cold water with tea tree oil.
Remove carpet from bedroom if possible.
Apoquel for feline atopy
Not FDA approved for use in cats.
Ortalda C, et.al “Oclacitinib in feline
nonflea, nonfood-induced hypersensitivity
dermatitis: results of a small prospective
pilot study of client-owned cats.” Vet
Derm 26, 2015, pp 235-238.
.4-.6mg/kg bid x l4 days then sid x l4
days. Good improvement in 5/l2 cats.
Apoquel for feline atopy
Chang et al. “An experimental janus
kinase inhibitor suppresses eosinophilic
airway inflammation in feline asthma.”
ACVIM abstract.
Frank RK et al. “Use of oclacitinib
(Apoquel) for treatment of cutaneous
mastocytosis in a cat.”
.7mg/kg bid (.5-lmg/kg bid)-range
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9/2/2016
Thanks for your attention!
Any questions??
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