Pathology of the Integumentary System Flashcards
What are the top 10 reasons for vet visits?
- atopic or allergic dermatitis
- ear infection
- benign skin neoplasia
- pyoderma
- osteoarthritis
- periodontitis/tooth infection
- upset stomach
- intestinal inflammation/diarrhea
- cystitis/urinary tract disease
- anal gland sacculitis/expression
What is the main function of skin? What does desquamation mean?
protective barrier against fluid loss (hydrophobic), microbiologic agents, chemicals, and physical injury
dead skin cells are continuously shed
How does the skin provide photoprotection?
pigmentations from melanocytes and hair prevent solar damage
What are 6 additional functions skin?
- temperature regulation
- sensory perception (whiskers)
- nutrient storage
- absorptive surface (lotion, topicals)
- immunoregulation
- antimicrobial action
How does the skin aid in vitamin D production? What are the 2 major functions of vitamin D?
- epidermis converts provitamin D3 from UV light into vitamin D3
- vitamin D3 is hydroxylated in the liver into 25-hydroxyvitamin D3
- 25-hydroxyvitamin D3 is converted into the active form of 1,25-vitamin D3 in the kidney
- maintain calcium-phosphorus ratio
- regulate epidermal differentiation and proliferation
What is the skin a major indicator of?
general health and disease
- can see a problem without deep examination
What 5 characteristics are used to describe lesions?
- DISTRIBUTION: anatomic location, focal vs. multifocal, mucous membrane involvement, symmetry
- SIZE
- SHAPE
- CONFIGURATION
- TYPE: primary vs. secondary
Lesion symmetry:
Lesion configuration:
What are primary lesions? What are some examples?
lesion directly associated with the disease process
- macule/patch
- papule/plaque
- pustule
- vesicle/bulla
- wheal
- nodule
- cyst
What are secondary lesions? What are some examples?
modification of a primary lesion that results from evolution of that lesion, traumatic injury, or other external factors
- epidermal collarette
- scar
- excoriation
- erosion/ulcer
- fissure
- lichenification
- callus
What are 6 common examples of lesions that can be primary or secondary? What lesions are the best choice for biopsy?
- alopecia
- scale
- crust
- follicular casts
- comedo
- pigmentary abnormalities
primary lesions
What are 3 common color changes that can happen to skin?
- erythema - reddening
- hyperpigmentation - increase in pigment (dark, black)
- hypopigmentation - decrease in pigment (white)
What are macules/patches? What are 3 examples?
flat, circumscribed lesion of altered skin color < 1cm or > 1cm
- hemorrhage
- lentigo
- vitiligo
Macule/patch:
What are papules? What 2 things are they the result of?
solid elevated lesions < 1cm
- allergic reaction
- bacterial folliculitis
Papules:
What are plaques? What 2 things are they the result of?
flat elevations in skin > 1cm in diameter
- calcinosis cutis
- eosinophilic plaque (allergy)
Plaques:
What are pustules? What 2 things are they the result of?
circumscribed raised superficial accumulations of purulent fluids within the epidermis
- bacterial infection
- pemphigus foliaceous
Pustule:
What are vesicles/bullas? What 4 things are they the result of?
sharply circumscribed elevations of epidermis filled with clear fluid < 1cm or > 1cm
- viral infections
- chemicals
- burns
- autoimmune disease