Dermatology Flashcards
1
Q
dr derm word for itching
A
pruritic
2
Q
what meds can cause derm reactions
A
sulfonamides
penicillins
cephalosporins
3
Q
what are 2 examples of “common” systemic illnesses that can cause derm issues
A
hyperadrenocorticism
hypothyroid
4
Q
what is dermogram
A
lesion distribution chart
5
Q
what is primary derm lesion
A
Initial eruption that develops spontaneously directly related to underlying disease
appear & disappear quickly
6
Q
what is secondary derm lesion
A
evolve from 1° lesion or induced by pt response or external factors
stay around for longer than 1° lesion
7
Q
Macule
or
patch
A
Macule: change in skin color w/o inflammation < 1 cm
patch: change in skin color w/o imflammation > 1 cm
8
Q
purpura, petechial, ecchymoses
A
type of macule or patch caused by bleeding into skin
name NB size (eg. petechia = pinpoint, ecchymoses = bigger than pinpoint)
9
Q
Papule
A
small, solid elevation in skin up to 1 cm, (inflammation present)
10
Q
plaque
A
coalescence of papules forming flat topped elevation >1 cm
e.g. a hot spot great example!
11
Q
pustule
A
small elevation of epidermis filled w/ pus
12
Q
vesicle
A
elevation of pidermis filled w/ clear fluid
13
Q
bulla
A
vesicle >1 cm
14
Q
wheal
A
sharply delineated lesion of edema
in humans = hives
in animals = urticaria
ACUTE CS
15
Q
nodule
A
solid raised palpable lesion >1 cm
can include abscess (fluctuant lesion in dermis or SQ from pus)
16
Q
Nodule: Tumor
A
Large palpable mass - neoplastic
17
Q
cyst
A
epithelial lined cavity with solid or fluid material
- sebaceous most common
- arise from dermis layer structures not epidermis*
18
Q
alopecia
A
absence of hair from area where it is normally present
- Important to ask if pruritis present for ddx of endocrine dz or not (ectoparasite or something else)
19
Q
Scale
A
accumulation of loosse fragments of horny layer of skin
seborrhea sicca
seborrhea oleosa
20
Q
crust
A
accumulation of dried serum, exudate on surface of skin (scab)
21
Q
follicular casts
A
accumulation of keratin & sebaceous material stuck to a hair shaft
22
Q
comedone
A
dilated hair follicle filled w/ debris
another derm lesion that can be caused by hypothyroid or hyperadrenocorticism
23
Q
epidermal collarette
A
scale arranged in circular pattern
associated w/ pustule, vesicle or bullae
24
Q
scar
A
fibrous tissue has replaced the damaged dermis or s/c tissue
25
excoriation
linear abrasion of skin
- self trauma
26
erosion
shallow ulcer that does not break basal epidermal layer
27
ulcer
break in epidermis w/ exposure of dermis
28
fissure
linear cleavage (cracks) in epidermis or dermis caused by dz or injury
29
lichenification
thickening & hardening of skin
exaggerated skin lines
*sign of chronic issue, time enough for melanocytes to migrate to area causing pigmentation*
30
callus
localized hyperplasia of the stratum corneum of the epidermis caused by pressure or friction
## Footnote
*Elbows & lateral hock areas are common sites for callus formation in the dog*
31
name this skin parasite
demodex
32
what can be seen on this skin cytology
neutrophils & streptococci
33
what can be seen on this skin cytology
neutrophils & rods
34
what can be seen on this cytology
yeast & cocci
35
what is here
malassezia yeast
36
flourescence detected or not?
detected!
## Footnote
*now if confirmation needed can pluck some hairs with known fluorescence and place in DTM*
37
When is a fungal culture indicated?
All cats w/ skin dz
Dogs w/ inflammatory skin lesions
38
Your dog has suddenly developed these primary lesions - what are they?
wheals
39
What is this primary lesion?
vesicle
40
What is this organism?
*Malassezia pachydermatitis*
41
Which test is best to identify know environmental allergens causing atopy, after performing your initial dermatological exam?
intradermal allergy test
42
What is the most common cause of pruritus in a 4 month old dog?
Flea bite dermatitis
43
What is the most likely cause for this skin condition?
Flea allergic dermatitis
44
Atopic dermatitis is cause by what type of reaction?
Type 1 hypersensitivity reaction
45
Flea allergic dermatitis is caused by what type of reaction?
Type 1 hypersensitivity
46
Which is the second most common cause for an allergic dermatitis in a 4 mo puppy?
Food allergens!
47
in dogs \<6 mos of age what is the order of the top three commom causes for an allergic dermatitis?
1. Fleas
2. Food allergens
3. Environmental allergens
48
in dogs \>6 mos of age what is the order of the top three commom causes for an allergic dermatitis?
1. Fleas
2. Environmental allergens
3. Food allergens
49
Which of the followind treatments doesn't show fair to strong evidence to control pruritis in an atopic dog?
1. Glucocorticoids (Prednisolone)
2. Cyclosproine A (Atopica)
3. Antihistamines (Chlorpheniramine)
1. Skin lipid therapy (Duoxo)
3. Antihistamines (Chlorpheiramine)
## Footnote
*show weak evidence of effectiveness!*
50
Carbohydrates is the most common type of food allergen in dogs & cats
True or False
False!
## Footnote
* #1 = proteins*
* #2 = glycoproteins*
51
Hydrolysed food diets can be used for food allergy dogs. Which statement is false?
1. Protein particle sizes are \<3000 to 10,000 Daltons in most foods
2. Hydrolysed food is more unpalatable compared to regular diets
3. Owner compliance is easily obtained
4. The lipid & carbohydrate source is also hypoallergenic
4. The lipid & carbohydrate source is also hypoallergenic
52
Which one of the following products would give you good local & environmental control in a dog dxd w/ FAD
1. Frontline (fipronil)
2. Advantage (imidocloprid)
3. Permethrin dip
4. Capstar (nitenpyram)
2. Advantage (imidocloprid)
53
An owner has decided on intradermal allergy testing & hyposensitisation. According to literature - what % of dogs will get a good to excellent control of atopic dermatitis through hyposensitisation?
1. 100%
2. 75%
3. 50%
4. 25%
3. 50%
54
Which ONE of the following is not a way to diagnose contact dermatitis?
1. Skin bx & histopathology
2. Patch test
3. Corticosteroid response
4. Mechanical barrier (jacket/jersey)
3. corticosteroid response
55
what type of pyoderma is this
surface pyoderma = hot spot
56
what type of pyoderma is this
superficial pyoderma = pustules
57
what type of pyoderma is this
superficial pyoderma = papules or pustuls
58
what type of pyoderma is this
deep pyoderma
59
what type of pyoderma is this
deep pyoderma
60
what are the characteeristics of surface pyoderma
mixed bacterial population
cytology critical
never culture
Tx: topical
61
what are the characteristics of superfcial pyoderma
overwhelmingly *Staphylococcus*
cytology suportive
_s__ometimes_ culture
Tx: systemic & topical
62
what are the characteristics of deep pyoderma
Mostly *Staph.* but can be mixed
Cytology often negative
Frequently cultured
Tx: systemic, long term, topical
63
when is culture mandatory
intracellular rods on cytology
hx of MSRP, MSRA
64
what are benefits of topical tx
helpful
decr. duration of systemic Abs
prophylactical use
little to no side effects
65
indication for benzoyl peroxide product
pyoderma w/ oily seborrha or comedones
66
indication ofr chlorhexidine product
pyoderma w/ dry seborrhea or normal skin/coat
67
what are the 2 special topicals
Mupirocin
silver sulfadiazine
68
mupirocin info
bacteriostatic @ low conc. / bactericidal @ high conc.
effective vs G + including MRSA
69
silver sulfadiazine
topical sulfonamide/silver antibacterial
used on burns
activity vs *Pseudomonas*
can be prepared w/ water for ear administraion
70
what are 1st tier systemic Abs for empiric tx
1st gen cephalosporins = cephalexin
amoxi/clav
clindamycin
71
what are 2nd tier empirical Abs
sulfas
erythromycin
lincomycin
doxycyline
72
what are 2nd tier based on C/s results ideally
chloramphenicol
rifampin
amikacin
73
what are 3rd tier LAST RESORT based on c/s results Abs
fluoroquinolones
3rd gen cephalosporins
***_USE ONLY IF:_* _no other antibiotic is a feasible option_**
**_culture shows suceptibility_**
74
how long to tx pyoderma
superficial:
3-4 wk min
1 wk beyone resolution
deep
3-12 wks
2 wks beyond resolution
signs often appear improved but don't stop tx prematurely
75
what is another name for acute traumatic pyodermatitis
hot spot
76
what is a common superficial pyoderma puppies get
puppy pyoderma or impetigo
77
what type of pyoderma is nasal folliculitis/furunculosis
superficial & deep pyoderma
78
what type of pyoderma is chin acne or chin pyoderma
deep pyoderma
79
what type of pyoderma is a lick granuloma
deep pyoderma
very common
AKA: acral lick dermatitis
80
what are the CS of mucocutaneous pyoderma
mucocutaneous swelling, erythema, crusting
affects lps symmetrically, commisures affected
81
what is the pathogenesis of pyotraumatic dermatitis
2o to underlying dermatitis (flea allergy)
82
CS of hotspots
lesion, red, moist, exudative, crusting
denuded
painful
lesions in areas of primary irritation
83
Dx & tx of hotspots
typical lesions w/ associated cause
response to tx
antibacterial disinfectant
antibioti/steriod
seek predisposing cause
84
pathogenesis of impetigo & CS
bacterial dz caused by ***Staphylococcus spp.***
young dogs
poor husbandry
Vesicales/ pustules
non-follicular pustules
ventral hairless areas
85
Dx of impetigo
typical CS
cytology
tx: antibacterial shampoos
toical antibiiotic washes/creams
86
pathogenisis of superficial pyoderma
S*taphylococcus pseudintermedius*
superficial hair follicle
self trauma
parasistic infestation
**folliculitis may progress to furunculosis to cellulitis**
87
3 most common causes of folliculitis in dogs
bacterial
dermatophytes
*Demodex*
88
CS of superficial pyoderma
tiny pustules with hair shaft protruding from center
follicular papule
patchy focal alopecia (moth eaten)
epidermal collarettes
scaling - seborrhea
hyperpigmentation or excoriations
89
Dx of superficial pyoderma
recognition of lesions
cytology
* degen. meutrophils, phagocytosed cocci, proteinaeous backround
90
tx of superficial pyoderma
Abs 21-28 days min
***_1 WK PAST RESOLUTION_***
antibacterial shampoo
91
what is important to recognize about deep pyodermas
there could be underlying disorder
92
pathogenesis of deep pyoderma
bact adhesion is prerequisite
bacteria can produce toxins
compromised skin defense \> infection 2o usually, try to find underlying dz
*Staphylococcus pseudintermedius*
allergy most common predisposing cause
follicular pathology
Ehrlichia, Distemper (dogs), retrovirus (cats)
93
CS of deep pyoderma
breeds: GSDs, Bull terriers
deep draining tracts, clusters of ulcers, necrohemorrhagic purulent bullae or abscesses
94
What is a ddx for deep pyoderma in light haired dogs
SCC
95
what about pyoderma in cats
feline pyoderma is very rare!
96
Dx of deep pyoderma
cytology
* pyogranulomatous exudate
* cocci found
histopathology
* biopsy - infection may mask underlying dz
* allergy = flea, food, atopy
bact culture and antibiogram
97
what are the rules when tx deep pyodermas
use B-lactamase resistant penicillins
## Footnote
**if multiple organisms cultured - TX *S. pseudintermedius* first!**
**dosage must be high enough**
**tx long**
98
common Abs for deep pyodermas
Amoxi/clav
cephalexin
clindamycin
99
pathogenesis of Actinomyocosis
*Actinomyces* organisms
trauma, penetrating wounds
CS:
SQ abscesses, draining tracts
Exudates, thick, yellow-grey, hemorrhagic, foul smelling +/- sulphur granules
100
Dx Actinomyces
Anaerobic culture
**DDx nocardiosis**
Tx: surgical debulking
clindamycin
**Px for cure is guarded!**
101
pahtogenesis of nocardiosis
G + filmentous aerobe
CS same as *Actinomyces*
pyothorax
102
Dx of nocardiosis
FNA/cytology
Histopathology
Culture
Tx: surgical debulking, drainage
Px: guarded
103
pathogenesis of opportunistic myobacteriosis
saprophytic mycobacterium
CS: slow developing, sq nodules, etc.
104
Dx of *Mycobacterium*
cytology
histopathology
culture
Tx: wide surgcal excision
105
pathogenesis of skin fold pyoderma aka intertrigo
skin folds
maceration
superficial infection
CS: lip folds in spaniels, facial folds in bulldogs, tail root folds, vulva folds, body folds in Shar Pei
106
Dx & Tx of intertrigo
Dx: clinical presentation, signalment
Tx: shampoos, rinses, topcal Abs
107
etiology of *Malassezia* dermatitis
dogs - *Malassezia pachydermatis*
cats - *M. sympodialis & globosa*
ear (otitis externa), lip folds, ventral neck, axilla, interdigital, perianal. May generalize! **CHECK FOLDS! CHECK EARS!**
commensal - 2o infections
hypersensitivity to yeart product & antigens
108
signalment seen w/ *Malassezia* dermatitis
WHWT
109
what is malassezia associated with
allergic dermatitis
endocrinopathies
keratinization disorders
immunosuppression
110
CS malassezia
pruritus
malodor
erythema, greasy scaly plaques
paronychia (nail inflammation)
111
CS for dogs & malassezia
concurrent underlying dz
rancid like odor
ears: black wax & rancid
hair: red-brown color
112
CS for cats & malassezia
Rare
## Footnote
**immunosuppressive dz (FIV, FeLV)**
113
dx malassezia
cytology
\>2/HPF (1000x) important
114
tx of malassezia
id & tx underlying factors if possible
topical: anti yeast shampoos 2-3 x wk
systemic: ketoconazole, itraconazole (better \< hepatic side effects)
115
pathogenesis of dermatophytosis
* Microsporum canis (NB), M. gypseum, Trichphyton metagraphytes*
* 70% are M. canis*
fungal spores can last long in environment
young, immunosuppressed
* FeLV, FIV
* *E. canis*
* endocrinopathies
* malignancies
* steroid use
*
116
what is important to remember about dermatophytosis
**ZOONOTIC**
*M. canis* also the **most common fungal infection in humans**
117
Dx dermatophytosis
Wood's lamp
mocroscopy of hair pluck
fungal culture
biopsy
**DDx in dogs: bact folliculitis, demodecosis**
**facial lesions (dogs) - pemphigus foliceous/erythematosus**
118
mgmt of dermatiophytosis
tx underlying dz, tx source, tx organizm
topical therapy: clip around lesions/wb
topical shampoos
systemic tx: griseofulvin, ketoconazole, itraconazole
6-12 mos
119
cattery/multi-cat households dermatophytosis management
separate infected animals
tx individuals
toothbrush cultures of all cats
decontaminate environment
120
