Skin Flashcards
How does antibiotic resistance of MRSI occur
acquisition of mecA gene which encodes a penicillin binding protien (PBP2a) that has a lower binding affinitiy for beta lactams
What are risk factors for MRSI
use of fluoroquinolones; IV catheterization; more than 10 vet staff employed; post-surgery site infection
What are abx commonly used to treat MRSI
doxycyclyline and chloramphenicol
How are burns classified
on body surface area and depth of tissue
Describe the total body surface area measurements in adapted to animals
Rule of nines
Head/Neck, each front limb = 9%
Each pelvic limb, dorsal trunk, ventral trunk = 18%
What is the severity associated with TBSA in burns
Local burn < 20% less likely for SIRS
Severe burn > 20-30% Very likely SIRS
> 50% TBSA very poor prognosis
Describe a first degree burn
Epidermis only
Painful, hyperemic
Describe second degree burns
Epidermis and upper portions of dermis: pain, blistering, hair intact
If deeper portions of dermis but not complete can see yellow white skin, lost of hair (pulls out), pain only with deep pressure
Describe third degree burns
Epidermis and entire dermis
black letheary skin; eschar is sensitive to touch
Hair pulls out easily
Describe fourth degree burns
epidermis and entire dermis, deeper tissues (connective, bone, vessels etc)
Black letheary skin; eschar is sensitive touch
Hair pulls out easily
Which burn categorization method has been validated in small animals
None
What is the local response to burn
Cells closest to heat source undergo coagulation and vascular thrombosis
Surrounding tissue affected by blood stasis and edema from capillary leak syndrome
Above plus hypoperfusion lead to ischemia
How does hypoxia worsen with burns
Edema from hypoalbuminema and vasoactive substances thromboxane and inducible NO worsen hypoxia
How long before closure of burn may be considered
Up to 3 days to declare itself, may be up to 7 days.
How does frostbite result in injury
Formation of ice crystals resulting in varying degrees of severity similar to burns
Describe type 1 hypersensitivity reactions- skin
angiodema, uticaria, erythema
IgE- antigen complex binds to mast cells and basophils
Describe type 2 hypersensitivity reactions - skin
Vesicles, bullae, erosions, mucocutaneous junctions
IgM and IgG cytotoxic
antigen-antibody binding
Describe type 3 hypersensitivity reactions - skin
Uticaria, ulceration, pitting edema, wheals, papules, pinnae foot pads; MC junctions
IgG immune complexes deposited in endotheilium of vessels