Derm 3+4 Flashcards
1
Q
Mycotic skin disease (ex. ringworm)
A
- Microsporum canis: small animal
- Love stratum corneum layer and hair shafts
o **Do NOT have to enter the living skin tissue to cause disease - ZOONOTIC
- Asymptomatic cats (Ex. long haired, Persian): toothbrush technique
2
Q
Malassezia pachydermatis
A
- Lipophilic yeast (normal in ear canal and skin): “snowman” on slide
- Microclimate or host defenses changed
- Mostly interdigital, otic, perianal, and intertriginous (SPOTS THAT RUB)
o Warm, moist environment
3
Q
Demodicosis
A
- Juvenile dogs (got it from dam) or adult cats (with underlying allergic skin disease)
- Underlying disease
- *hardest to get rid of=love hair follicles (DEEP)
o Need 3 negative skin scrapings before you can say it is gone - Usually have a low number of skin normally
- Periorbital alopecia
- Can happen with steroid use
4
Q
Sarcoptic mange
A
- Pigs and dogs
- Intense pruritus
- Highly contagious
- Zoonotic
5
Q
Cheyletiella
A
- Bigger mites
- “walking dandruff” (will see if moving up the hair shaft)
- *superficial
6
Q
Chorioptic mange
A
- Cattle
- Head and tail
- Younger animals
7
Q
Myiasis
A
- Larval infestation by dipterous flies
- Blow flies and flesh flies
o Eggs deposited in wounds or on soiled hair/wool=larvae secrete proteolytic enzymes=holes and ulcerated skin
8
Q
Screwworms
A
- Cochilomyia hominivorax
- Tropical climates
- Deposit eggs in wounds or near mucocutaneous junctions =develop into L1 and feed on tissue =soon develop into L2
9
Q
Cutaneous habronemiasis
A
- Habronema or Draschia sp. Larvae
- Skin that is traumatized or moist
- Medical canthus of eye or prepuce
- Unable to penetrate normal skin
- *southern US problem
10
Q
Urticaria
A
- Hives
- Edema of superficial dermis
11
Q
Angioedema
A
- Edema of deep dermis and subcutis
- *takes longer
12
Q
Urticaria and angioedema
A
- Most common in dogs and horses
- Immunological causes: food, drugs, antisera, insects
- Non-immunological causes: heat, stress, exercise
13
Q
Atopic dermatitis
A
- Genetically predisposed inflammatory and pruritic allergic skin disease
- *Type I hypersensitivity
- Average onset: 1-3 years
- 3-15% of skin disorders
o Predominately percutaneous absorption of allergens in genetically predisposed animals - *2nd most common hypersensitivity in dogs
- *reoccurs and does not really matter what time of the year
- *do skin panel on=most wont do it
14
Q
Flea bite hypersensitivity
A
- Mixed type I and type IV
- Dogs and cats
- Pruritic popular dermatitis=self inflicted trauma and chronic lichenification
- Fibropruritic nodules: core of collagen covered by a hyperplastic epidermis
15
Q
Mosquito bite hypersensitivity
A
- Type I hypersensitivity
- Primarily on external nose
- Erythematous papules
- Hypopigmentation or hyperpigmentation
16
Q
Food allergy
A
- Common
- *mixed Type I and type IV
- Diagnosed more often in dogs than cats
- Any age
- Need strict elimination trial to determine foods animals are allergic to diagnose
o ELISA not reliable predictor
17
Q
Contact dermatitis
A
- Type IV reaction
- From chemicals (ex. in shampoos, plastic food dishes)
- Pruitus with self-inflected trauma
- Regions in contact with antigen
- Spongiotic superficial perivascular dermatitis, epidermal hyperplasia with varying numbers of eosinophils
18
Q
Pemphigus
A
- Gross transient vesicles or bullae
- Histo: acanthosis
- *type II reactions
- Autoantibodies against proteins responsible for cell adhesion
- Damage to desmosomes=acantholysis=formation of bullae
19
Q
**Pemphigus foliaceous
A
- Vesicles become pustules
- Secondary crusts and scales
- Dog/cat NOSE first=periorbital, ears, neck and ventral abdomen
- Horse: subcorneal pustules
- Dog: stratum spinosum
20
Q
Systemic lupus erythematous
A
- *Type III
o Defective T cell suppressor and cytokine dysregulation
o Immune complexes formed and deposited in skin - Basal cell or keratinocyte degeneration
- Antinuclear antibody (ANA) titers
21
Q
Hyperthyroidism
A
- Cats
- Self-inflected alopecia
- ‘rough’ appearance
- Thin
22
Q
Hypothyroidism
A
- Most common dermatosis in dogs
- Age: over 6 years
- Intolerance to cold
- Obesity
- Dry hair coat
- Alopecia
- Adnexal atrophy
- Dermal edema
- Hyperpigmentation
- Scaling
23
Q
Mucinosis
A
- Unusually finding with HYPOthyroidism
24
Q
Hyperadrenocorticism
A
- Cortisol excesses
o Alopecia
o Thin skin
o Hepatomegaly
o Dystrophic calcification
o Infections
25
Q
What are the causes of hyperadrenocortism?
A
- Pituitary
- Adrenocortical
- Iatrogenic
- *second most common endocrine dermatosis in dogs
26
Q
Calcinosis cutis
A
- Secondary to hyperadrenocortism
27
Q
Hyperestrogenism
A
- Males and females
- Sertoli cell tumor (cryptorchid)
o Ovarian cysts - Atrophied hair follicles (female: swollen vulva)
28
Q
Post-clipping alopecia
A
- Prolonged telogen phase breeds
o Ex.**Chow-chow and Pomeranian - *takes 6-12 months to grow
29
Q
Alopecia X (ex. chow-chows and Pomeranians)
A
- Dogs with normally PLUSH hair coats (1-2 years old)
- Head and distal extremities are often spared of alopecia
- Normal thyroid and glucocorticoid levels
- Skin biopsy samples with telogen follicles (retained hair shafts and flame follicles)
- *some respond to melatonin
30
Q
Diseases of keratinization
A
- Abnormal sebaceous gland function AND/OR hyperkeratosis
- Orthokeratotic vs. parakeratotic
- Primary: common
- Secondary: inflammation
- Change from non-pathogenic resident bacteria to pathogenic: coagulase-positive staphylococci
31
Q
Seborrhea sicca
A
- Dry form
o Dry skin, white-gray scales
32
Q
Seborrhea oleosa
A
- Greasy form
o Scaling and excessive brown to yellow lipids that adhere to skin and hair
33
Q
Ichythyosis
A
- Cattle and dogs
- Scaly, cracked skin
- Orthokeratotic
- ‘ichthy’=fish
34
Q
Ichythyosis fetalis
A
- Often aborted or still born
- Calves and puppies
35
Q
Digital hyperkeratosis
A
- Key lesion of pemphigus
- But can happen without pemphigus
- Ex. large breed dogs
- Treat with moisturizer and ‘sand’ them down (ex. pumice stone)
36
Q
Zinc responsive dermatosis
A
- Dogs (ex. malamutes and huskies), pigs
- Lesions: scaling and crusting with marked diffuse parakeratosis
- Pathogenesis
o Inherited reduced ability to absorb Zn from intestine
o Large breed, rapidly growing pups: low zinc diets - Give zinc and goes away
37
Q
Eosinophilic plaques
A
- Common in cats
- Possible link to hypersensitivity reactions (look for underlying allergy)
38
Q
Eosinophilic granulomas
A
- Horses, dogs, cats
- Flame figures, eosinophil degranulation
- Lesions: nodular dermatitis, indolent ulcers (LIPS)
39
Q
Juvenile cellulitis (sterile granulomatous dermatitis)
A
- Puppy strangles
- No microorganism IDed (sterile lesion)
- Secondary bacterial infections
- Lesions: pustular and nodular dermatitis with edema (mostly facial)
40
Q
Squamous cell carcinoma
A
- Very aggressive
41
Q
Injection site fibrosarcoma
A
- Almost always grow back
- Why do it over a limb so you can ‘cut’ it off
42
Q
Lipoma
A
- *Cut them open=they like to hide mast cell tumors (ex. boxers)
- Increase with age
- Various sizes
43
Q
Histiocytoma
A
- Usually regress on their own within 2 months and won’t occur again
o If see macrophages, plasma cells, lymphocytes=evidence of regression - Usually under 2 years old
- VERY common (Ex. Boston terriers around eyes)
o Eyebrow area (hairless and not too big)
o When angry red=point of regression
44
Q
Mast cel tumor
A
- VERY aggressive
o Spread their effect around! (metastasize locally and far away!)
45
Q
Basal cell tumor
A
- RARE
- Black=where melanin hangs out (basement membrane) (DDx: melanoma is more common)
- Multinodular, raised
- May or may not be malignant
- Excised and submitted
- Don’t usually reoccur
46
Q
Sebaceous gland hyperplasia
A
- Nodules that come out of hair follicles
- VERY common (ex. little skin tag)
- Many small dogs have them
- Malignant=very rare
47
Q
Biopsy
A
- Do NOT scrub area=removes important diagnostic lesion
- Surgical prep if doing excision, but NOT for punch biopsy
- Mark direction of hair with marker
- Include normal and abnormal samples
- Sample edges of ulcers
- Margins are often determined by differentials
- 3cm guideline
- Mark to orientate if subQ mass (sutures, safety pin, etc.)
- *valuable info lies in the CRUST!
