L1: Intro to Dermatology (Marsella) Flashcards
1 and 2 reason dogs visit vets
1) ear infections
2) skin allergies
components of history
onset
length of time of disease
seasonality
relatives
zoonosis
hx of medications (abx, flea control, topical therapy, special diet, supplements, etc.
environment/life style/health status/diet
Primary lesions***
macule papule plaque pustule vesicle bulla nodule wheal tumor
macule**
area of skin altered in color but NOT elevated
- can be red, pigmented, depigmented
- if >1cm diameter called patch
papule**
solid raised lesions that has distinct border and is less than 1cm in diameter
-look like red bumps
plaque**
elevated lesion with flattened top, greater than 10mm in size
- next lvl up from papules; combo of individual papules
- skin may become keratinized or ulcerated
pustule**
elevations filled with pus
- common lesion in bacterial infections, and other inflammatory skin diseases
- follicular or non-follicular
- may contain neuts, eos, +/- acantholytic cells, bacteria
3 causes of folliculitis in dog***
Bacterial (ie. Staphylococcus) <– most common
Demodex
Dermatophytes
nonfollicular differentials for papular/pustular eruption
flea food contact scabies drug eruption dermatomyositis sterile pustular diseases autoimmune
vesicle**
small (<1mm), clear fluid-filled blister
-may be caused by acute contact dermatitis and some autoimmune skin diseases
bulla**
clear fluid-filled blister >10mm in diameter
-causes: burns, contact dermatitis, drug rxn, autoimmune disease
nodule**
firm lesions that extend into the dermis or SC tissue
tumor*
swelling or enlargement
-usually (not always) neoplastic
wheal (hive)**
sharply circumscribed skin elevation produced by edema of the superficial dermis
- typical of allergic rxns
- diascopy (can be blanched)
- due to vasodilation
- usually linked to allergic rxn
secondary lesions***
epidermal collarettes scale crust scar ulcer excoriation lichenification hyperpigmentation hyperkeratosis
epidermal collarettes**
2ary from previous pustules
-leaves ringworm-like lesion
scale**
flake of abnormal or compacted epithelial cells
crust**
dried exudate
-often has leukocytes and bacteria
scar**
fibrotic area resulting from healing of a wound or lesion
-typically assoc. with alopecia, depigmentation, and/or thinner dermis
ulcer**
loss of substance on a cutaneous surface exposing inner layers or tissues
- may imply full thickness loss of epidermis
- what’s leftover when bulla breaks
- seen with autoimmune disease in feet, oral cavity
excoriations**
superficial erosion
-usually implies scratching or abrasion
lichenification**
thickening of skin
-secondary to chronic trauma/inflammation
hyperpigmentation**
increased pigmentation
-commonly assoc. with lichenification
hyperkeratosis***
thickening of the stratum corneum due to an inc. number of keratinized cells
-common in cocker spaniel feet
