Dermatology

Question 1

What does MRSI stand for and what is the mechanism of resistance for MRSI?

Answer 1

Methicillin resistant staphylococcus infections
Resistant by bacterial acquisition of the mecA gene which encoded a penicillin-binding protein (PBP2a). has much lower binding affinity for beta-lactams

Question 2

What could these clinical signs be indicative of, skin abscess, otitis externa, wounds, pyoderma (papules, erosions, crusts, exudates?

Answer 2

superficial methicillin -resistant pyoderma, demodicosis, Malassezia, cutaneous drug eruption, vasculitis, pemphigus foliaceus

Question 3

give 3 risk factors for MRSI

Answer 3

Suspect if px with non-healing wound, folliculitis or abscess present after completing ab tx, esp beta-lactams.

Use of fluoroquinolones

Intravenous catheterization

More than 10 veterinary staff employed

Postsurgical site infection

Question 4

How do you confirm a MRSI?

Answer 4

Culture and sensitivity using oxacillin

PCR (gold standard)

Latex agglutination testing to detect PBP2a (penicillin-binding protein)

Question 5

How are burns classified?

Answer 5

% body surface

depth
(1 degree. superficial
2 degree. epidermis and superficial part dermis
2 degree. epidermis and deeper part of dermis
3 degree. full thickness
4 degree. full thickness with extension to muscle, tendon, bone)

Question 6

What is the rule of nine in burns?

Answer 6

percentage of total body, surface area of burn

Head and neck, each forelimb 9%

Dorsal trunk, ventral trunk, each hind limb 18%

Question 7

What is the % for local burns and % for severe burns?

Answer 7

Local <20%. Severe >20-30%

Question 8

fill in missing words regarding burns

first degree. depth: X. appearance: erythematous, painful to touch. Healing: X, time X with X management

second degree. depth: X appearance: epidermis will X, X leakage occurs. hair follicles will X, X to touch. healing: by epithelization from the wound margin with X scar. Time X days

second degree. depth: X
appearance: skin appears x, hair follicles will X, decreased X . Healing: by X and X but X is significant without X.

third. Depth: X. appearance: skin is X, X, eschar insensitive to touch. Healing: requires intensive x intervention. Possible skin grafts and flaps

fourth degree. Depth X: appearance: x Healing: need X to prevent scaring that could restrict joint movement.

Answer 8

first degree. depth: SUPERFICIAL, EPIDERMIS ONLY. appearance: erythematous, painful to touch. Healing: RAPID, time REEPITELISATON IN 1 WEEK WITH TOPICAL WOUND MANAGMENT

second degree. depth: EPIDERMIS AND SUPERFICIAL PART OF DERMIS appearance: epidermis will CHARRED AND SLOUGHS, PLASMA leakage occurs. hair follicles will SPARED, PAINFUL to touch. healing: by epithelization from the wound margin with MINIMAL scar. Time 10-21 days

second degree. depth: EPIDERMIS AND DEEPER PART OF DERMIS appearance: skin appears BLACK OR YELLOW-WHITE, hair follicles will DESTROYED, decreased PAIN SENSATION. Healing: by CONTRACTION and EPITELIZATION BUT SCARRING is significant without SURGICAL INTERVENTION

third. Depth: FULL THICKNESS (ENTIRE DERMIS AND DERMIS). appearance: skin is BLACK, LEATHERY, eschar insensitive to touch. Healing: requires intensive SURGICAL intervention. Possible skin grafts and flaps

fourth degree. Depth FULL THICKNESS WITH EXTENSION TO MUSCLE, TENDON, AND BONE: appearance skin is BLACK, LEATHERY, eschar insensitive to touch (same as third): Healing: need SKIN GRAFTS AND FLAPS to prevent scaring that could restrict joint movement.

Question 9

When is cardiovascular shock, pulmonary, and metabolic derangements likely to occur in burn px?

Answer 9

If more than 20% of body surfaces is burned or its second or third degree burns

Question 10

What is an eschar? How long does it take to form?

Answer 10

deep cutaneous slough of tissue composed of full-thickness degenerated skin. Black, firm, thick movable crust that separates from the surrounding skin. Purulent exudates often lie beneath the eschar, particularly if it covers deep or extensive injuries, and sepsis can result if it is not treated promptly. Takes 7-10 days to form.

Question 11

What are the two main local responses in burn px that are most dramatic within first 12 h?

Answer 11

Capillary thrombosis and plasma leakage -> burn wound oedema

Question 12

List 6 systemic issues seen in burn px

Answer 12

Anemia, hypoproteinemia, hyperNa or hypoNa, hyperkalemia or hypokalemia, acidosis, coagulopathy, oligura, prerenal azotemia (these in first line are from SACCM)

ARDS, capillary leak, myocardial dysfunction, poor perfusion

Hypoalbuminemia, vasoactive substances (NO, thromboxane) worsen hypoxia

Marked hyperalgesia due to cytokines (IL1, IL 6, TNFa)

Anaemia (haemolysis from direct damage and through damaged microcirculation), hypoproteinaemia, hyper/hypoNa, hyper/hypoK, met and resp acidosis, oliguria, prerenal azotaemia, disseminated intravascular coagulation (DIC)

Question 13

What fluid rate is recommended in the first 34 h in burn px? Both saccsm recommendation and the parkland formula.

Answer 13

1-4 ml/kg x % TBSA burned (SACCM)

Fluid rate 4ml/kg x TBSA for the first 24 h, with half of the amount administered in the first 8 h, the remaining over the remaining 16 h - called consensus formula (formerly Parkland formula). Reduce with 25-30% in cats

Question 14

How should you treat a burn px that has just been burned?

Answer 14

if presents within 2 h, cool with cold water (not below 3 degrees) for 30 min under running tap (convection). (don’t use ice water and ice packs (vasoconstriction and necrosis) (conduction))

Question 15

name 6 things to consider in burn victim tx

Answer 15

cool, fluid rate/metabolic derangements, nutrition, analgesia, antimicrobial therapy, wound care

Question 16

how do you treat the wound of a first degree and superficial second degree burn?

Answer 16

daily lavage (hydrotherapy 8psi using 19 g needle and 35 ml syringe), conservative debridement and topical treatment initially.

Question 17

Name one effect of aloe vera as topical treatment in burn px

Answer 17

Anti-thromboxane effect that prevents vasoconstriction and thromboembolic seeding of the dermal vasculature

Question 18

In burn px: What type of activity and against which type of pathogens has silver sulfadiazine effect? Name 3 advantages and 3 disadvantages

Answer 18

Bactericidal. Broad spectrum, most Gram positive, most gram negative, MRSA, yeast (candida), molds

+ painless, soothing, penetrates eschar, no metabolic side effects, sustained release products available

• possible delayed wound healing, argyria (skin turns blueish), local hypersensitivity reaction

Question 19

In burn px: What type of activity and against which type of pathogens has honey effect? Name 4 advantages and 2 disadvantages

Answer 19

Broad spectrum, most gram positive, most gram negative, MRSA.

+ improved healing rate, less wound contraction, decreased hyper granulation, increased wound strength, creates more sterile environment, provides physical barrier to wound
Honey antimicrobial due to high osmolarity, acidity, and hydrogen peroxide content. Decreases oedema, accelerates sloughing of necrotic tissue, and provides a rich cellular energy source, promoting a healthy granulation bed.

-Local hypersensitivity reaction, tissue dehydration

Question 20

In burn px what should be monitored around day 2-7, and from day 7?

Answer 20

between day 2 and 7: check for anaemia, DIC; immune dysfunction, SIRS; infection

from day 7: check for hyperthermia, hypoxia, pneumonia, sepsis, wound demarcation

Question 21

what are the most common complications in burn px?

Answer 21

scarring, and wound contraction. infections, hypothermia, intra-abdominal hypertension, and abdominal compartment syndrome

Question 22

at what pressure should intra-abdominal hypertension be treated?

Answer 22

pressures > 10 cm H2O be considered mild elevations in IAP. I treat when IAP > 20 cm H2O in dogs and cats

Question 23

what are the two phases in burn px according to Vaughn?

Answer 23

The resuscitation phase. Also called hypodynamic or ebb phase (immediate -72 h)

The hyperdynamic hypermetabolic phase . Also called flow phase (3-5 days after injury – 24 months)

Question 24

What two mechanism does the body use to protect against frost bite?

Answer 24

Arteriovenous anastomose and vein-artery-vein triads

Question 25

Name 2 causes for immune mediated and 2 non-immune mediated drug eruptions

Answer 25

Immunemediated: Hypersensitivity reaction I-IV like:
Toxic epidermal necrolysis, pemphigus foliceus, erythema multiforme
Haptens and prohaptens (small molecule bound to proteins) etc
Ex drugs: antibiotics, nsaid, opioids, methimazole, sulphonamides, hydralazine, vaccines, trimspulfa, cephalexin, oxytetracycline, penicillin, levothyroxine, amoxiclav

Non immunemediated: Altered arachidonic acid metabolism, complement activation, danger particles like cytokines and cell debris etc

Question 26

Give 4 conditions associated with vasculitis

Answer 26

babesiosis, rocky mountain spotted fever, histoplasmosis, FIP, lymphoma – vaccines – food allergy – medications (human serum albumin, carbamizole, fenbendazole)

Question 27

What are the 3 phases of wound healing and how long do they last? Give two examples for each phase of whats occuring

Answer 27

Inflammation and debridement immediate – 5 days. Haemorrhage, vasoconstriction and PLT aggregation initially, then vasodilation. Neutrophils and macrophage activity

Proliferative phase 4 days – 3 weeks. Angiogenesis, granulation tissue formation, epithelization

Maturation phase 17-20 days wound contraction, remodelling of collagen fibre bundles, progressive gain of tissue strength

Question 28

What are 4 different way for a wound to heal/close

Answer 28

Primary closure

Delayed primary closure (after delay but before granulation tissue)

Secondary closure (after granulation tissue, usually more than 5 days)

Secondary intention healing

Question 29

What are the 4 different wound classifications?

Answer 29

Clean: Atraumatic, surgically created under aseptic conditions (e.g., incisions)

Clean contaminated: Minor break in aseptic surgical technique (e.g., controlled entry into the gastrointestinal [GI], urogenital, or respiratory tracts) in which the
contamination is minimal and easily removed

Contaminated: Recent wound related to trauma with bacterial contamination from street, soil, or oral cavity (e.g., shearing or bite wound); can also be a surgical wound with major breaks in asepsis (e.g., spillage from the GI or urogenital tracts)

Dirty or infected: Older wound with exudate or obvious infection (e.g., abscess in a bite wound, puncture wound, or traumatic wound with retained devitalized tissue); contains more than 105 organisms per gram of tissue

Question 30

What is the classification of open fractures?

Answer 30

Grade I: small break in skin <1 cm caused by bone penetrating inside to out, surrounding tissue mild to moderately contused

Grade II: soft tissue trauma > 1 cm contiguous with the fracture, often external trauma, a (e.g., bite wound, low-velocity gunshot injuries)

Grade III: extensive soft tissue injury, commonly in addition to a high degree of comminution of the bone (e.g., distal extremity shearing wounds, high-velocity gunshot injuries)

Question 31

What is the optimal lavage pressure for a wound and how is it achieved?

Answer 31

7-8 psi achieved using 18-19 gauge hypodermic needle attached to 35 ml syringe (or 16 gauge needle and 35 ml syringe)

Question 32

Name 4 types of non adherent dressings

Answer 32

Alginates, foams, hydrogels, hydrocolloids, transparent film

Question 33

Name 1 contraindication each for gauze, polyester film with cotton, calcium alginates, hydrogels, hydrocolloids, foams, polyurethane films

Answer 33

Gauze: non appropriate with healthy granulation tissue or when trying to get wound to epithelialize

polyester film with cotton: may promote excessive granulation tissue

calcium alginates: do not use over exposed tendon, bone or necrotic tissue

hydrogels: may promote excessive granulation tissue

hydrocolloids: not for use in exudative or infected tissue, may promote excessive granulation tissue

foams: reduced granulation, may cause maceration if overlap skin

polyurethane films: may cause bacterial proliferation and may cause maceration if overlap skin

Question 34

What are the uses/benefits and contraindications/disadvantages for polyurethane film?

Answer 34

Uses:
Occlusive but permeable to air and water vapor but impermeable to fluid and microorganisms.
Autolytic debridement
Covering for sutured wounds

Contraindications:
Because of occlusive, adherent property, may cause bacterial proliferation and tissue maceration. Should be changed every 1-3 days

Question 35

Why should a tegaderm dressing be changed every 1-3 days?

Answer 35

Because of occlusive, adherent property, may cause bacterial proliferation and tissue maceration.

Question 36

What are the uses/benefits and contraindications/disadvantages for foam dressings?

Answer 36

Uses: absorbent and comfortable. Used in deep wounds with minimal exudate. Promotes epithelialization and contraction.
Contraindications: reduced granulation. May cause maceration if overlapped on skin

Question 37

What are the uses/benefits and contraindications/disadvantages for hydrocolloids dressings?

Answer 37

Uses: autolytic debridement. Increases epithelization and comfort. Promotes granulation.
Contraindications: not for use in exudative or infected wounds. Can promote exuberant granulation.

Question 38

What are the uses/benefits and contraindications/disadvantages for hydrogel dressings?

Answer 38

Uses: absorbs minimal exudate. Autolytic debridement. Rehydrates to soften dry wounds.
Contraindications: discontinue after healthy granulation tissue is present because it can promote exuberant granulation.

Question 39

What are the uses/benefits and contraindications/disadvantages for calcium alginates dressings?

Answer 39

Uses: absorbs heavy exudate. Pad, ribbon, or fibre forms gel when absorbing exudate. Haemostatic, favours epithelization and granulation.
Contraindications: do not use over exposed tendon, bone, or necrotic tissue

Question 40

What are the uses/benefits and contraindications/disadvantages for polyester films with cotton dressings?

Answer 40

Uses: used primarily during epithelization phase on surgical wounds, wounds with good granulation tissue and with minimal exudate
Contraindications: may promote excessive granulation tissue

Question 41

What are the uses/benefits and contraindications/disadvantages for impregnated gauze dressings?

Answer 41

Uses: added zinc, iodine, or petrolatum nonadherent and helps prevent desiccation. Absorbs bacteria and exudate
Contraindications: although it increases wound contraction, it can delay epithelization

Question 42

What are the uses/benefits and contraindications/disadvantages for gauze dressings?

Answer 42

Uses: inexpensive, readily available. Wet-to-dry nonselective debridement
Contraindications: not appropriated when healthy granulation tissue is present or when trying to get wound to epithelialize