Defense & Barriers 2: Eosinophilic Dermatoses Flashcards
commonality of EOSINOPHILIC DERMATOSES in cats, dogs, horses?
**for the species it’s NOT common in, elaborate
COMMON in CATS/HORSES, UNCOMMON IN DOGS
can still HAVE eosinophils on DOG skin disease, just not in BIG AGGREGATE LESIONS like in cats/horses
dogs & symmetrical alopecia? (*in context of CATS?)
ONLY DOGS, NOT CATS CAN HAVE SYMMETRICAL ALOPECIA due to ENDOCRINOPATHY
in CATS, more likely SELF-INDUCED from PRURITIC DISEASE
eosinophilic reaction pattern: FELINE SYMMETRICAL ALOPECIA
differentials? (3 main causes, 2 main topics under first each w/ 3) –> include COMMONALITY & which is EXCLUSIONARY
which OVERALL CAUSE is MOST COMMON?
(1) SELF-INFLICTED/over-grooming, **MOST COMMON)
PRURITIC disease
1. ALLERGIC = atopy, insect hypersensitivity, food allergy
2. INFECTIOUS = staphylococcal, malassezia, dermatophytosis
3. PARASITIC = DEMODEX GATOI*** COMMON, scabies, otodectes (mange), cheyletiella
PSYCHOGENIC/STRESS-induced
**RARE, diagnosis of EXCLUSION
(2) ATROPHY of hair follicles
–> PARAENOPLASTIC/METABOLIC syndrome: OLDER cats but RARE
–> PANCREATIC or HEPATOBILIARY origin: MORE COMMON
(3) CONGENITAL pattern alopecia
–> common in SPHINX or DEVON REX
what does this trichogram show? what would it suggest in a cat with alopecia & pruritus?
shows BROKEN HAIR FOLLICLE
suggests that ALOPECIA is caused by OVER-GROOMING from TONGUE CAUSING DAMAGE TO FOLLICLE
most common REGIONS for FELINE SYMMETRICAL ALOPECIA caused by OVER-GROOMING? (5)
** which is most common?
regions?
1. ABDOMEN/GROIN** MOST COMMON
2. Caudal/medial thighs
3. Anterior forelimbs
4. Lumbosacral area (insects)
5. Flanks
5 step diagnostic approach for FSA?
(1) RULE OUT ECTOPARASITES (D. gatoi & cheyletiella) and SURFACE INFECTIONS (yeast and bacteria) by GIVING BRAVECTO
(2) Screen for DERMATOPHYTOSIS
–> Wood’s lamp exam & TRICHOGRAM
–> FUNGAL CULTURE if index of suspicion high, such as household members affected (new kitten w/ alopecia on ears)
(3) TIGHTEN UP FLEA CONTROL MEASURES if doubtful!
–> Might take several months to break reproductive cycle!
–> ALL ANIMALS NEED TO BE ON PREVENTATIVES!
(4) If none of those work, consider FOOD ALLERGY vs. ATOPY
–> If OVER-GROOMING is steroid-responsive, then psychogenic cause unlikely
–> Diet trial for food allergy
(5) If NOT PRURITIC DISEASE (allergic, infectious, or parasitic), then PSYCHOGENIC ALOPECIA. RARE
LIST of FELINE eosinophilic reaction patterns (4, include 3 subsets for last one)
- FELINE SYMMETRICAL ALOPECIA
- MILIARY DERMATITIS
- MOSQUITO HYPERSENSITIVITY
- EOSINOPHILIC DERMATITIS COMPLEX…
indolent ulcer of the lip
eosinophilic plaque
eosinophilic granuloma
identify & what eosinophilic reaction pattern is it a RULE-OUT DIFFERENTIAL of? –> give both the NAME and “lesion description”
DEMODEX CATI
RULED OUT in MILIARY DERMATITIS, “small, crusted papules”
diagnostic approach for “small, crusted papules?” (4)
what PATTERN is this? what species?
make number 4 the LAST RESORT & why
“small, crusted papules” = MILIARY DERMATITIS, FELINE EOSINOPHILIC REACTION PATTERN
(1) Rule out BIG 3 FOLLICULAR DISEASES with SCREENING TESTS…
DEMODEX CATI, BACTERIAL FOLLICULITIS (rare in cats), DERMATOPHYTOSIS
(2) If you suspect NEOPLASIA, then SKIN BIOPSY, but RARE.
(3) Depending on HISTORY and DISTRIBUTION pattern, determine if MILIARY DERMATITIS most likely. **Note that ANY PRURITIC DISEASE CAN CAUSE MILIARY DERMATITIS, most commonly PARASITIC
(4) HOLD OFF on DIET TRIALS/DRUGS due to EXPENSE and CHANCE OF ADVERSE EFFECTS. LAST RESORT.
identify lesion, what pattern is it? what species?
INDOLENT (RODENT) ULCER on UPPER LIP
this is part of EOSINOPHILIC DERMATITIS COMPLEX pattern in CATS, along with eosinophilic plaques & eosinophilic granulomas
EOSINOPHILIC DERMATITIS COMPLEX
= basic definition & what 3 things make it up
what species?
FELINE
= a group of reaction patterns that are (initially) eosinophilic and probably SHARE COMMON PATHOPHYSIOLOGY and CAUSES, including…
- INDOLENT (RODENT) ULCER
- EOSINOPHILIC PLAQUES
- EOSINOPHILIC GRANULOMAS
INDOLENT (RODENT) ULCER…
what reaction pattern/species?
= definition/location
3 differentials we need to consider?
clinical signs? (3, how ulcers are formed, what happens in chronic cases, what’s usually present)
2 pathophysiology hypotheses?
EOSINOPHILIC DERMATITIS COMPLEX/FELINE
= POORLY or NON-HEALING ulcers of the UPPER LIP and/or ORAL COMMISSURE that WILL NOT HEAL ON ITS OWN
3 DDxs?
(1) EOSINOPHILIC REACTION
–> any pruritic allergic or parasitic disease can cause an indolent ulcer
–> MOST COMMONLY = FLEA ALLERGY
–> LESS COMMONLY = dermatophytosis
(2) TOXICITY & PHYSICAL TISSUE DAMAGE
–> Caustic chemicals
–> Chewing on electrical cord
(3) NEOPLASIA
–> Squamous cell carcinoma (malignant neoplasm of epithelium)
clinical signs?
1. ERYTHEMA/SWELLING –> EROSIONS –> ULCERS
2. for CHRONIC cases –> FIBROSIS
3. usually SECONDARY INFECTIONS present (CRUSTED or ABSCESSATED lesions) so RESPONSIVE TO ANTIMICROBIALS
pathophysiology?
1. NOXIOUS eosinophilic contents causing TISSUE DAMAGE
2. SELF-INJURY from OVER-GROOMING secondary to PRURITIC disease
identify LESION, EOSINOPHILIC REACTION PATTERN, and WHAT TREATMENT WOULD BE BEST
lesion = (chronic) INDOLENT (RODENT) ULCER
part of EOSINOPHILIC DERMATITIS COMPLEX pattern in cats
treatment with ANTIBIOTICS + STEROIDS is best bc it’s chronic
INDOLENT (RODENT) ULCER…
what reaction pattern? what species?
diagnosis to CONFIRM? **why is this difficult?
ACUTE and CHRONIC treatment options? (2)
EOSINOPHILIC DERMATITIS COMPLEX/FELINES
diagnosis?
–> can do BIOPSY to confirm, but by the time BIOPSY READ, NO LONGER EOSINOPHILIC INFILTRATES
treatment?
–> ACUTE = GLUCOCORTICOIDS
–> CHRONIC = ANTIBIOTICS + STEROIDS
identify lesion, reaction pattern & species
EOSINOPHILIC PLAQUE
part of EOSINOPHILIC DERMATITIS COMPLEX
CATS
identify lesion, reaction pattern & species
EOSINOPHILIC PLAQUE
part of EOSINOPHILIC DERMATITIS COMPLEX
CATS
identify lesion, reaction pattern & species
**WHAT BREED IS THIS?
EOSINOPHILIC PLAQUE
part of EOSINOPHILIC DERMATITIS COMPLEX
CATS, **THICK IN SIAMESE
EOSINOPHILIC PLAQUES…
what reaction pattern/species?
4 descriptors to describe it?
2 descriptors that are OFTEN present?
2 locations it’s OFTEN in?
4 DDXs (under 2 big categories)?
diagnosis? (2)
treatment? (1)
EOSINOPHILIC DERMATITS COMPLEX/FELINES
4 terms?
1. FLAT
2. ERYTHMATOUS
3. RAISED
4. CIRCUMSCRIBED
2 terms for OFTEN?
1. EXUDATIVE
2. PRURITIC
2 locations it’s often in?
1. ABDOMEN
2. MEDIAL THIGHS
4 DDxs?
(1) NEOPLASTIC plaques
–> LYMPHOMA
–> MAST CELL TUMORS
(2) MIXED INFLAMMATORY plaques
–> TRAUMA/NON-HEALING wounds w/ SECONDARY BACTERIAL INFECTION
–> PRIMARY infection = DERMATOPHYTOSIS
diagnosis?
–> if MOIST = IMPRESSION SMEARS
–> if DRY = FNA/BIOPSY
treatment?
–> if SECONDARY INFECTION, treat with TOPICAL CHLORHEXIDINE (antiseptic)
EOSINOPHILIC GRANULOMA…
what reaction pattern/species? (+ special one)
= what do the lesions look like?
where do they occur? what 3 places most COMMONLY? what other place can they occur/clinical sign?
3 MAIN differentials? (w/ subs: 4 for first, 3 for second, 0 for third, 2 for fourth)
diagnosis? (2)
EOSINOPHILIC DERMATITIS COMPLEX/FELINES
**also HORSES but usually NON-PRURITIC
lesions?
= NODULAR LESIONS that are YELLOW to PINK
where?
–> occur ANYWHERE
–> most commonly in ORAL CAVITY, HEAD, & FEET
–> also occur on CHIN and cause FAT LIP
3 differentials?
(1) NEOPLASTIC
–> Lymphoma
–> Mast cell tumors
–> Sarcoma
–> Metastasis from other areas
(2) PRIMARY INFECTIONS
–> Bacterial
–> Fungal
–> Mycobacterial
(3) TRAUMA/NON-HEALING wounds w/ SECONDARY INFECTIONS
(4) STERILE/MIXED INFLAMMATORY CELL GRANULOMAS
–> Post-vaccine reactions
–> Insect bites
DIAGNOSIS
–> CYTOLOGY via FNA
–> BIOPSY
identify lesion, reaction pattern, species
EOSINOPHILIC GRANULOMAS
EOSINOPHILIC DERMATITIS COMPLEX
CATS & HORSES (horses are NON-PRURITIC)
identify lesion, reaction pattern, species
EOSINOPHILIC GRANULOMAS
EOSINOPHILIC DERMATITIS COMPLEX
CATS & HORSES (horses are NON-PRURITIC)
if we see EOSINOPHILIC GRANULOMAS (nodules) on the FOOTPADS, then…
what differential is FIRST on the list?
what species/etiology?
what therapy does it respond to?
if it DOESN’T respond to this therapy, what is needed?
FIRST DIFFERENTIAL = PLASMA CELL PODODERMATITIS
species/etiology?
–> CATS ONLY
–> IDIOPATHIC
therapy?
–> RESPONDS TO DOXYCYCLINE, and if not then it needs IMMUNOSUPPRESSIVE therapy!
identify lesion, pruritic or not, reaction pattern, species
EOSINOPHILIC GRANULOMA on the CHIN
usually NON-PRURITIC
EOSINOPHILIC DERMATITIS COMPLEX
FELINE & HORSES
DESCRIBE the TWO LESIONS found here & DIRECTION!
what 2 regions is this most common?
why are the lesions in the direction they’re in? (hint: a PROTEIN is involved)
2 lesions = EOSINOPHILIC GRANULOMAS (nodules) & PLAQUES in LINEAR PATTERN
2 regions?
1. CAUDAL THIGHS
2. ABDOMEN
they’re LINEAR because…
–> cat is OVER-GROOMING itself due to PRURITUS
–> cat is DEPOSITING FEL-D-1 ALLERGEN PROTEIN into SKIN and CAUSING REACTION
label the 3 lesions
identify the lesion & reaction pattern
EOSINOPHILIC GRANULOMA
EOSINOPHILIC DERMATITIS COMPLEX
identify disease
MOSQUITO HYPERSENSITIVITY REACTION
identify disease
MOSQUITO HYPERSENSITIVITY REACTION
identify disease & what pathognomonic thing in histo should be present!
HERPESVIRUS-ASSOCIATED FACIAL DERMATITIS
INCLUSION BODIES SHOULD BE PRESENT
identify disease
HERPESVIRUS-ASSOCIATED FACIAL DERMATITIS
identify disease
HERPESVIRUS-ASSOCIATED FACIAL DERMATITIS
MOSQUITO BITE HYPERSENSITIVITY…
what kind of pattern is this? **unique
what animal is most likely to be affected? at what times?
6 most common lesion distributions?
3 ACUTE lesions?
2 CHRONIC lesions?
5 DDxs/reasons as to why for 3 of them?
diagnosis options? (3, which is the best?)
ETIOLOGY-SPECIFIC reaction pattern
who’s affected?
–> OUTDOOR CATS in the EVENINGS (when mosquitoes most active)
6 most common lesions?
1. muzzle
2. peri-areolar
3. peri-auricular
4. nasal planum
5. ear tips
6. foot pads
ACUTE lesions…
1. miliary dermatitis
2. erosions/ulcers
3. edema
CHRONIC lesions…
1. leukoderma
2. scarring alopecia
5 DDxs?
1. pemphigus foliaceus = LEUKODERMA & ULCERATION of NASAL PLANUM/TIP
2. herpesvirus-associated facial dermatitis = NASAL PLANUM & MUZZLE
3. demodicosis
4. dermatophytosis = EAR TIPS & MUZZLE
5. neoplasia
MOSQUITO BITE HYPERSENSITIVITY
how to diagnose? (start with what’s done FIRST w/ 5 subsets, then 2 options)
treatment
treatment? (3, 2 subsets for first)
diagnosis?
1. RULE OUT OTHER DDxs VIA BASICS (scraping, cytology, wood’s lamp, trichogram, fungal culture)
2. INTRADERMAL ALLERGEN TESTING = whole mosquito might NOT have enough allergen!
3. SKIN BIOPSY w/ HISTOPATHOLOGY can be SUGGESTIVE & help RULE OUT AUTOIMMUNE diseases
treatment?
1. STEROIDS to help stop SCRATCH CYCLE
–> topical not good for cats
–> ORAL PREDNISOLONE or METHYLPREDNISONE
–> PARENTERAL METYHLPREDNISOLONE ACETATE (Depo-Medrol)
- RESTRICTION from OUTDOORS, especially at DUSK/AFTER DARK
- REPELLENT via SERESTO collars
LIST the 2 canine eosinophilic reaction patterns
CANINE EOSINOPHILIC FURUNCULOSIS of the FACE
CANINE EOSINOPHILIC DERMATITIS with EDEMA (Well’s-Like Syndrome)
define furunculosis
= RUPTURE of the hair follicle with INFLAMMATION in the SURROUNDING DERMIS
identify disease
CANINE EOSINOPHILIC FURUNCULOSIS of the FACE
identify disease
CANINE EOSINOPHILIC FURUNCULOSIS of the FACE
CANINE EOSINOPHILIC FURUNCULOSIS of the FACE…
etiology?
who’s most likely to get it? (4 descriptors?)
rate of onset?
4 clinical signs? (+ including one medication response)
5 DDxs?
diagnosis? (2, including one that might not be necessary)
treatment? (1)
etiology?
= for EOSINOPHILIC causes, only BITING/STINGING insects, like YELLOW JACKETS or HONEYBEES!
who’s most likely? = A DOG WHO’S…
1. YOUNG
2. CURIOUS
3. MEDIUM-LARGE BREED
4. DOLICOCEPHALIC
rate of onset? = ACUTE
clinical signs?
1. LESIONS on DORSAL MUZZLE and NOT NASAL PLANUM
2. LESIONS have progressed RAPIDLY from PAPULES/EDEMA –> ULCERATIVE HEMORRHAGIC lesions that CRUST
3. PAINFUL
4. NO RESPONSE TO ANTIBIOTICS
5 DDxs?
1. demodicosis
2. dermatophytosis
3. pemphigus foliaceus
4. muzzle pyoderma
5. neoplasia
diagnosis?
1. CYTOLOGY via FNA or IMPRESSION SMEAR = look for lots of eosinophils
2. SKIN BIOPSY is UNNECESSARY if hx of insect sting present, but can help rule out PEMPHIGUS!
treatment?
1. STEROIDS = PREDNISONE at MODERATE-HIGH DOSE
identify disease
CANINE EOSINOPHILIC DERMATITIS with EDEMA (canine Well’s-like syndrome)
identify disease
CANINE EOSINOPHILIC DERMATITIS with EDEMA (canine Well’s-like syndrome)
CANINE EOSINOPHILIC DERMATITIS with EDEMA (canine Well’s-like syndrome)…
etiology? (3 subs)
history? (2)
clinical signs? (4, 3 subs on third, last one is WEIRD)
diagnosis? (1, ruling out between what 2 diseases?)
treatment? (1 that works, 1 ineffective)
likelihood of RECURRENCE/CHRONICITY is (high/low)?
etiology? = likely HYPERSENSITIVITY reaction to…
1. INSECT or ARACHNID allergen
2. DIETARY or AIRBORNE allergen
3. DRUGS
history?
1. ACUTE/SUDDEN lesion formation with KNOWN antigen exposure
2. BEFORE skin signs have BLOODY DIARRHEA or have USED ANTI-DIARRHEALS
clinical signs?
1. EDEMA
2. BRIGHT RED, ERYTHEMATOUS, VIOLACEOUS MACULES, WHEALS, PAPULES from VASODILATION
3. SYSTEMIC signs (pyrexia, malaise, hypoproteinemia)
4. REACTIVE EOSINOPHILIC LYMPHADENOPATHY
diagnosis?
1. must do SKIN BIOPSY to rule out VASCULITIS and ERYTHEMA MULTIFORME
treatment?
1. usually STEROIDS at ANTI-INFLAMMATORY DOSE!
2. ANTIHISTAMINES alone are NOT effective
LIKELIHOOD OF RECURRENCE/CHRONICITY IS LOW
