Integument (Ginn) Flashcards
1
Q
objectives
A
- recognize and describe gross lesions
- diseases common per species
- form ddx
- know primary vs secondary lesion: give/recognize example of each
2
Q
Common presenting complaints
A
- odor
- hair loss
- itchiness
- pigment change
- lumps, bumps
- scales
- crusts
- sores
3
Q
Functions of skin
A
- Temp and blood pressure regulation
- flud regulation
- protection: barrier
- sensation
- nutrient metabolism
- immune functions: SALT
4
Q
Microscopic anatomy of skin
A
- Epidermis
- can involve hair follicles (they are invagination of epidermis)
- Dermis
- Adnexa
- hair follicle
- apocrine gland
- sebacious gland
- Panniculus
5
Q
basal layer of skin
A
germinal layer
6
Q
Epidermis
A
- Stratum corneum
- Stratum granulosum
- Stratu spinosum
- Stratum basale
7
Q
Diagnostic approach
A
- Signalment
- age of patient, breed, sex, color
- age of lesions
- History
- duration, pruritus, other animals
- Distribution and character of lesions
- Response or failure to respond to treatment
- overall health status
8
Q
Blue dobermans
A
follicular dysplasia
9
Q
Primary lesions most useful for
A
dx of dz
10
Q
Secondary lesion
A
evolution
11
Q
Acanthosis
A
- Epidermal change: hyperplasia
- usually affects stratum spinosum
- regular
- Irregular: yeast
- papillated
- pseudocarcinomatous
12
Q
Yeast infection
A
- acanthosis - lichenification
13
Q
Hyperkeratosis
A
- inc width of stratum corneum
- orthokeratotic: too much, or not exfoliated
- parakeratotic: too much with retained nuclei
14
Q
Ichthyosis
A
- congenital dz too much growth stratum corneum
- good env for microbe growth and infections
- orthokeratotic
*golden retrievers
15
Q
Superficial necrolytic dermatitis
A
- hyperkeratosis of foot pads
- metabolic dz
- assoc with liver disease
16
Q
Dyskeratosis
A
- premature keratinization of cells in epidermis
- epidermal change
- can be precancerous change
- often see with parakeratosis as well
17
Q
Necrosis
A
- Epidermal changes
- full thickness
- apoptosis: single cell or clusters of cells
18
Q
Erythema multiforme
A
- tissue reaction to something
- scattered, transepidermal reaction
- Clinically
- erosions
- ulcers
- crusts
19
Q
Cutanous atrophy
A
- fewer cells, smaller cells
- epidermis
- dermis
- follicles
- alopecia
*associated with cushings
20
Q
Edema
A
- Epidermal changes
- intercellular = spongiosis
- intracellular
- hydropic degeneration
- ballooning degeneration
- could lead to sub-epidermal vesicle
21
Q
Full thickness epidermal necrosis
A
- toxic
- burn
- vasculitis
- painful, life-threatening
22
Q
Acantholysis
A
- loss of cohesion between keratinocytes due to breakdown of cell to cell attachments
- two main mechanisms
- type II hypersensitivity: pemfigus foleacious
- diff from infection
- enzymatic destruction
- type II hypersensitivity: pemfigus foleacious
23
Q
Pemphigus foliaceus
A
- primary lesion is pustule
- secondary lesion is crust
24
Q
classic distribution of pemfiigus foleaceus
A
across nasal planum
25
vesicles/bullae
* epidermal changes
* fluid filled
* within epidermis or at epidermal/dermal junction
26
Vesicular or pustular pathogenesis
* Marked spongiosis, hydropic or ballooning degeneration
* Enzymatic destruction
* Immune destruction
* acantholysis
* other
* mechanical destruction
* burn
* friction
* Genetic structural defects
27
Vesicle
* Severe epidermal edema
* severe contact hypersensitivity
* sting/bite (type 1)
28
Epidermal-dermal separation
* immune mediated
* primary lesion: vesicle
* secondary lesion: ulcer
29
Pustules
* epidermal changes
* Pustule
* neutrophilic: infection
* eosinophilic: atopy, hypersensitivity
* pautrier's microabscesses: malignant leukocytes
* crust
30
changes in pigmentation
* hyperpigmentation
* chronic inflammation
* idiopathic
* hypopigmentation
* prob with basal membrane
* only pigmented part of skin
31
Follicular changes
* Hyperkeratosis
* Atrophy
* Folliculitis
* Furunculosis
* Dysplasia
32
DDX folliculitis
1. bacterial infection
2. dermatophytes
3. demodecosis
33
Folliculitis/furunculosis
* grossly, folliculocentric papules or nodule
* patcy alopecia
* ulcerative draning lesions in severe cases
* inflammation targets hair follicle
* leukocytes are within the wall or lumen of follicle
* furunculosis
* wall of follicle is destroyed by infiltrate and contents of hair follicle are in dermis
34
Dermal changes
* Inflammation
* Edema
* urticaria/Angioedema
* immunologic (Type 1) and nonimmunologic causes
* Mucinosis: chinese shar pei
* Collagen
* fibrosis
* degeneration
* mineralization
* Elastin: elastosis
* calcinosis cutis
* hyperadrenocorticism
* Subcutis
* panniculitis
* fat necrosis
35
Vessels
* Vasodilation
* erythema, edema
* Vasculitis
* thrombosis
* ischemia
* edema
* hemorrhage
* atrophy
36
When bx
* devastating dz
* neoplasm
* unsuccessful tx
* immediate answer
* primary lesions, leading margins, edges of ulcers, crusts
* multiple sites
37
Pattern DX of skin and disease
* Based on types of cells present and their distribution in conjuction with types of changes discussed
* Rarely pathognomonic
* suggestive of pathogenesis and categories of disease
38
Cellular infiltrates
* Neutrophils
* active inflammation
* Eosinophils
* allergic or ectoparasites
* Mononuclear phagocytes
* persistent antigen in tissue
* Lymphocytes/plasma cells
* Mast cells
* resident cells, hypersensitivity
39
Perivascular Dermatitis
* most common type
* generic response to skin injury
* suggests **hypersensitivity**
* aggregates of inflammatory cells around vessels
* acute/chronic
40
Interface dermatitis
* hydropic degeneration/apoptosis in basal layer
* band of lymphs, plasma cells, macs at epidermal/dermal junction
* pigmentary incontinence
* +/- vesicles at interface
\*almost always immune mediated
41
Interface dermatitis
pathogenesis
* cytotoxic T-cell attack on keratinocytes or melanocytes, or basement membrane components
* non-immune mediated damage
* unknown
42
Uveodermatologic syndrome
* akitas
* attack on melanocytes
* uveitis is painful
43
Interface Dermatitis
Discoid lupus
* depigmentation around face and nose
44
**Whats the target of interface dermatitis?**
**TQ**
* Anything at the basal region, dermal epidermal junction
45
**Common pathogenesis in interface dermatitis?**
* Immune mediated
* DKH: melanocytes
* Discoid lupus
* systemic lupus
\*depigmenting
46
Vasculitis
* Leukocytes within walls of capillaries and venules
* evidence of vessel damage
* edema/hemorrhage
* fibrinoid necrosis/thrombosis
* leukoclasis
* Overall skin changes will reflect degree of vascular damage
* mild-atrophy and alopecia
* severe-cutaneous infarction and ulceration
* If multicentric, lesions at
* tail
* footpads
* ears
\*vasculitis common in dogs and horse
47
Vasculitis pathogenesis
* Type III hypersensitivity: immune complex deposition in vessels
* Primary bacterial skin disease
* bacterial septicemia
* systemic infection with endotheliotropic organism
* rickettsia
48
Vasculitis-pigs
* Erysepalothrix rhusiopathiae - septic emboli
49
Nodular to diffuse dermatitis
* dermis +/- panniculus
* have nodules or diffuse infiltrates of leukocytes
* Types of leukocytes present help point to a cause
* Pathogenesis
* persistence of antigens in tissue stimulate a cell mediated immune response
50
Nodular to diffuse dermatitis
causes
* Fungi - zygomeycetes, others
* deep pyo
* higher bacteria - acid fast bacteria
* parasites
* protozoans
* oomycetes
* pythium, lagenidium
* Algae
* idiopathic - sterile
* foreign material
* neoplasms
* histiocytic
* eosinophilic granulomas
51
Dematiaceus fungi
* fungi pigmented in tissues
* nodular to diffuse dermatitis
* ex: horse traumatic implantation
52
Vesicular or pustular
* Vesicles or pustules are within or below the epidermis
* intraepidermal
* subcorneal
* suprabasilar
* subepidermal: splits epidermis and dermis
53
Vesicular or pustular pathogenesis
* marked spongiosis, hydropic or ballooning degeneration
* enzymatic destrution
* immune destruction
* mechanical destruction
* burn
* friction
* genetic structural defects
54
Vesicular or pustular, determining specific process
* need to know
* level of vesicle formation
* degree and type of celular infiltrate
* signalment
* distribution of lesions needed to determine specific dz process present
55
Level of vesicle is critical
to determine specific disease process present
56
Subcorneal vesicle/pustule
* superficial pyoderma
* pemphigus foliaceus
57
Suprabasilar vesicle/pustule
* pemphigus vulgaris
58
Subepidermal vesicle/pustule
* bullous pemphigoid
* SLE (systemic lupoid erythematosus)
* TEN (Toxic epidermal necrosis)
* burns
* EB (epidermal lysis bullosa)
59
TEN vs EB
* TEN: epidermis dead
* EB: viable epidermis
60
Folliculitis/furunculosis
* grossly, folliculocentric papules or nodule
* patchy alopecia
* severe cases may have ulcerative draining lesions
* Inflammation targets hair follicle
* leukocytes are within the wall or lumen of the follicle
* furunculosis: wall of follicle destroyed by infiltrate and contents of hair follicle are in dermis
61
Folliculitis/furunculosis
* colonization of hair follicle by organism most common
* bacteria, dermatophytes, mites
* immune mediated
* idiopathic
62
Folliculitis/furunculosis other causes
* feline acne
* pelodera
* arthropod bites (common in fl)
* eosinophilic folliculitis
63
**What are most common causes of folliculitis in dogs?**
**TQ**
1. **Bacteria**
2. **Dermatophytes**
3. **Mites**
64
Panniculitis
* Subcutaneous fat focus of inflammation
* Grossly-papules and nodules that drain
* may have oily exudate
* Histologically
* inflammation of subcutis - nodular to diffuse
* same list of agents as nodular to diffuse
* part of systemic dz
* pancreatitis
* idiopathic sterile nodular panniculitis
65
Commn DDX for panniculitis in cats
* Atypical mycobacteria
* Nocardia
66
Atrophic Dermatoses
* symmetric hypotrichosis, thin skin
* comedones
* telangiectasia
* hyperpigmentation
* focal atrophic dermatotsis - partial ischemia
67
Atrophic dermatoses most common cause
Hormonal disturbance
68
Atrophic dermatoses
* epidermal and follicular atrophy with hyperkeratosis
* sebaceous gland atrophy
* hyperpigmentation
* may or may not se inflammation
* hormonal imbalance
* hyperadrenocorticism
* hypothyroidism
* sex hormone imbalance
* ischemia if focal
* need additional clinical and biochemical info for definitive dx in most cases
69
Cats hyperadrenocorticism
**fragile skin**