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284 Cards in this Set

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What is reddening of the skin called, and what causes it?
What is a disease associated with it?

Erythema
Due to congestion of capillaries (hemorrhage)
Associated with Lyme's Disease
What is a flat lesion of altered skin color, less than 1.0cm2?
Where is it located in the skin?
Macule, purpura (petechia = pinpoint)
Purpura is caused by hemorrhage
Located in epidermis
What is a flat lesion of altered skin color, greater than 1.0cm2?
Patch
What is a solid elevation of skin, less than 1.0cm2?
Where is it located in the skin?
What is a disease associated with it?
Papule
Below the epidermis
Associated with Psoriasis
What is a large elevation formed by coalescing papules?
Plaque
What is a skin elevation that is elevated greater than 1.0cm2?

Where is it located?
Nodule

Dermis or subcutis
What is a elevated area caused by derma edema?
Wheal (hives or urticaria)

Can coalesce and form plaques - are transient.
What is another name for a small blister (less than 1.0cm2) located within the epidermis or below the epidermal-dermal junction?
What is a disease associated with it?
Vesicle
Larger vesicle = blebs or bullae
Associated with Foot & Mouth Disease
What is a small accumulation of pus within the epidermis or hair follicle?
What is associated with it?
Pustule (basically a superficial abscess that contains neutrophils and bacteria)
Pustular dermatitis due to Staph aureus
What is a feature of a skin leasion where there is an encircling scale with its free edges toward the center?

What does it represent?
Epidermal collarette

Represents earlier bulla, vesicle, or pustule
Scales are accumulations of what layer of the epidermis

What disorder is this seen with?
Stratum corneum
Seen in chronic dermatitis and hyperkeratosis
(specifically hyperkeratosis from seborrheic dermatitis)
What is another name for a scab and what does it usually consist of?
Crust
Consists of dried exudate, such as serum, blood, pus, bacterial debris, etc
(can arise secondary to things such as bacterial dermatitis)
What are focal depression of the skin where there is partial loss of the epidermis (but no involvedment with basement membrane)?
What does it result from?
Erosions
May result from ruptured vesicle or pustule, or trauma to the skin
What is a superficial erosion, which results in superficial loss of epithelium due to trauma?
Excoriation (due to things such as scratching)
What is a deep linear crack or groove in the epidermis, and it extends into the dermis (which disrupts the basement membrane)?
What causes this?
Fissure
Caused by drying or thickening of the epidermis (loss of elasticity)
What is the loss of epidermis to the level of at least the superficial dermis (which disrupts the basement membrane)?
What is a disorder associated with it?
Ulcer
Associated with severe ulcerative dermatitis (or lick granuloma)
What is the irregular thickening of the skin with creases and sometimes hyperpigmentation?
What is a disease associated with it?
What are two examples of lichenification?
Lichenification
Can be caused by fungal infection in a dog (Malassezie infection)
Acanthosis and Hyperkeratosis
What are epidermal proliferations, which give the epidermis a rough, warty appearance?
Verrucae
What kind of tissue makes up a scar, and replaces normal skin following injury or laceration to the skin?
Fibrous connective tissue
_______ is the thickening of the skin due to epidermal hyperplasia (especially the stratum spinosum). It is also know it as a ______.
It develops secondary to_______.
Acanthosis
Callous
Chronic infection
Normal epidermis is ______ cells thick.
6-10
_________ is the disruption of ________ (intercellular junctions) between keratinocytes.
Acantholysis
Desmosomes
Hyperkeratosis is an increase in the thickness of the_____ layer of the epidermis.
Stratum corneum
Hyperkeratosis is subdivided into to categories: ______, where cornified epithelial cells are anuclear; and______, where cornified epithelial cells have nuclei.
Orthokeratosis
Parakeratosis
An example of orthokeratosis is __________, where there is excessive crusting, scaliness, and greasiness of the skin.
Idiopathic seborrhea
[Idiopathic = unknown cause/origin
Seborrhea = excessive discharge of sebum from the sebaceous glands]
Idiopathic seborrhea results in increased production of corneocytes and visible scale.
________ is intercellular edema (edema in the interstitium).
Why does it develop?
Spongiosis
Develops as a sequela to inflammation
______ is the caused be intracellular (intracytoplasmic) accumulation of water, or ________________.
This can lead to ______ formation.
Ballooning
Hydroptic degneration
Vesicle

[cells accumulate water, rupture, and cause a vesicle]
What is marked acanthosis, that resembles a carcinoma? It can also be seen histologically when looking at equine ____ and bovine warts.
Pseudoepitheliomatous hyperplasia
Sarcoids
What is the disorder that is caused by melanocytopenia (or a lack of melanin production), and is characterized by expanding pale macules due to destruction of melanocytes?
It is thought to be an ______ disease.
Vitiligo
Autoimmune
The ____ is the largest organ in the body.
Skin
Skin is thickest on the ____ and lateral limbs, and thinnest on the ____ and inner thighs.
Dorsum
Ventrum
List of the 4 layers of the epidermis.

What is the 5th layer that is found in the foot pads of cats and dogs, and between what two layers is it located?
- Stratum corneum
- Stratum granulosum
- Stratum spinosum
- Stratum basale

5th - Stratum lucidum (located between corneum and granulosum)
Stratum lucidum contains the protein ______, which eventually becomes keratin.
Eleidan
How long does it take for the maturation of a keratinocyte?
Approximately one month
What is seborrhea?
What does it cause?
Excessive dishcharge of sebum from sebaceous glands.
It causes accelerated keratinization.
What is the function of melanocytes?
Which epidermal layer(s) are they found in?
Give hair and skin color
Basale & spinosum
________ are bone marrow-derived monocyte-macrophage cells that present antigens to T-lymphocytes. They are located in the _____ layer(s) of the epidermis.
Langerhans cells
Basale, spinosum, granulosum
What are the neuroendocrine cells that have tactile sensory perception? Where are they located in the epidermis?
Merkel cells
Basal layer
(cause Merkel cell carcinomas)
What structure separates the epidermis and the dermis?
What type of collagen anchors them together?
What cell junctions are found here?
Basement membrane
Type IV collagen
Hemidesmosomes
What structure consists of collagen and elastic fibers in a glycoaminoglycan matrix, and supports hair folicles, adnexal structures, nerves, and vessels?
Dermis
Skin has three roles in host defense:
1. Physical
2. Immunological
3. Reparative mechanisms
The main defense layer of the epidermis is the stratum _______.
Corneum
Sebaceous glands in the skin secrete sebum, which contains vitamin ___. This vitamin protects against antioxidants.
E
Melanin pigmentation functions to protect against _______.
UV light
The basement membrane, which lies between the _____ and the _____, functions to protect against the invasion of ______ cells.
Dermis & epidermis
Neoplastic
The _____ immune response functions during the first 7 days of exposure.
Innate
Keratinocytes in the stratum corneum of the epidermis contain ____ (cytokine), which is released against invading pathogens, and induces gene expression.
IL-1
Adaptive immunity involves __ and ___ lymphocytes, which increase by _____ expansion.
T & B
Clonal
During an adaptive immune response, a stimulus causes ____ cells and ____ cells in the dermis to phagocytize and process the agent.
Langerhan's
Dendritic
Uncontrolled immune response can lead to chronic inflammatory disorders. Name three.
Contact hypersentitivity (type IV, delayed-type)
Atophic dermititis (type I, immediate allergy against environment)
Lupus erythematous (type III, immune complex disease)
What are the two repairative mechanisms of the skin?
Healing by first intention
Healing by second intention
Explain healing by first intention.
Healing by first intention:
- Bring edges of wound together
- Macrophages remove debris/blood/etc
- New blood vessels sprout
- ECM is synthesized
- Basal cells --> hyperplasia --> covers defect in 3-5 days
Explain healing by second intention.
Healing by second intention:
- Edges of skin are NOT brought together
- CT is haphazardly made and arranged
- Disorganization = harder to immune cells to get to wound
- Proliferating fibroblasts = perpendicular to capillaries, and capillaries = perpendicular to skin surface???
- Tensile strength = diminshed as compared to first intention
Wounds should start healing on the _____ (inside/outside) and work their way ____ (out/in).
Inside
Out
_______ is an increase in the thickness of the stratum corneum.
Hyperkeratosis
What are four specific syndromes associated with orthokeratosis?
1. Idiopathic seborrhea (excessive crusting, scaliness, and greasiness of the skin)
2. Ichthyosis (genetic defect where skin is thickened and can crack into plates due to increased adherence of keratinocytes [prevents normal desquamination])
3. Vitamin A deficiency (causes xerophthalmia [dry cornea] because of lack of B-carotene)
4. Zinc responsive dermatitis (defect in metabolism of Zn (1) or inadequate Zn in diet (2))
What drugs can help cause hepatocutaneous syndrome?
Phenobarbital and phenytoin
Hepatocutaneous syndrome, also called _____ _____ ______, causes hypoaminoacidemia, which is the the presence of abnormally ____ (low/high) concentrations of ______ in the blood.
Superficial necrolytic dermatitis
Low
Amino acids
A clinical sign of hepatocutaneous syndrome in older dogs is that the ___ ___ are thickened and contain fissures and crusts. This is due to a _____ (inc/dec) epidermal turn-over due to _____ (inc/dec) availability of AA or the abnormal ___ (what element?) metabolism.
Foot pads
Decreased
Decreased
Zn
Hepatocutaneous syndrome causes epidermal lesions, and also is associated with _____ (liver/kidney/intestinal) disease.
Liver
Hepatocutaneous syndrome causes epidermal crusts and fissures, and also causes _____ in the liver, which causes the collapse of hepatic lobules.
Fibrosis
Acanthosis is a form of _________ (lesion term) that occurs because of hyperplasia, or an increase in _____ of cells in the epidermis.
Lichenification
Number
_______ is characterized by premature keratinization of viable cells in the epidermis. Why do epidermal cells stain brightly eosinophilic in this disorder
Dyskeriosis
Accumulation of keratin filaments
In what circumstancs is dyskeriosis seen?
1. Zn responsive dermatitis
2. Premalignant change in actinic keratitis
3. malignant change in squamous cell carcinoma
Programmed cell death is also called _____. Apoptotic keratinocytes resemble dyskeratotic keratinocytes because they stain _______. In apoptosis, this is because of a condensation of cytoplasmic________.
Apoptosis
Eosinophilic
Organelles
_____ is abnormal development of the keratinocytes that refers to alteration in size, shape, or organization. If these cells cross the basement membrane, they become _______.
Dysplasia
Neoplastic
What are three characteristics of abnormal cells?
1. Large nuclei
2. Multi-nucleated cells
3. Giant cells
4. Mitotic figures
5. Variance in cells
6. Vacuoles in cells
______ is the decrease in number and size of cells. What are two causes of this disorder occuring in the skin?
Atrophy

1. Cushing's
2. Localized ischemia (necrosis)
3. Severe malnutrition
Spongiosis is _______ edema. What are two causes of spongiosis?
1. Staphylococcus sp. (bacteria)
2. Malasezia ap. (fungus)
3. Poxvirus infection (virus)
_______ is the disruption of intercellular junctions. What is a cause of this?
Acantholysis

Pemphigus - a rare group of blistering autoimmune diseases that affect the skin and mucous membranes. When autoantibodies attack desmosomes, the cells become separated from each other and the epidermis becomes "unglued", a phenomenon called acantholysis
What are three causes of vesicles?
1. Epidermal edema (balooning degeneration)
2. Friction
3. Thermal burns
4. Acantholysis (autoimmune disease)
5. Viral infection (poxvirus)
What are two causes of pustules?
1. Bacterial infections
2. Pemphigus (autoimmune)
3. Feline eosinophilic granuloma
Hyperpigmentation occurs with the increased production of ______, or the increase in the number of _______. In addition, an increase in size of _____ granules can produce hyperpigmentation.
Melanin
Melanocytes
Melanin
What are two causes of hyperpigmentation?
1. Chronic inflammation
2. Endocrinopathies (Cushing's)
3. Photosensitivity (certain drugs)
Hypopigmentation can be _____ or _____ (causes). It can also be caused by a deficiency in ______ (mineral).
Congenital
Hereditary
Copper (Cu)
In dogs and cats, albinism is often associated with hypoplasia of _____ (organ) and _____ (condition).
Organ of Corti
Deafness
Hypopigmentation can be caused by a deficiency in cooper. This occurs because copper is needed for the synthesis of _______, which is needed for the synthesis of ______. This type of hypopigmentation is seen with excess ______ or _____ in the diet.
Tyrosinase
Melanin

Molybdenum
Sulfur
______ is a form of genetic hypomelanosis. It results in white patches of skin where there are no _______ or these cells can't produce _____.
Piebaldism
Melanocytes
Melanin
Pigmentary Incontinence, a type of hypopigmentation, refers to the loss of melanin from what layer of the epidermis? Melanin accumulates in what cells in the dermis?
Basilar layer
Macrophages
PIgmentary incontinence is seen in what diseases? Macrophages in the _____ (skin layer) are filled with melanin granules.
1. Vitiligo (autoimmune)
2. Chronic inflammation
3. Discoid lupus erythematosus (autoimmune)
Macrophages
_____ is a form of hypopigmentation that can be caused by burns, trauma, etc. Melanin is found in the superficial dermis in what cells?
Leukoderma
Macrophages
________is the decrease or loss of pigment in hair.
Leukotrichia
Dermal atrophy is a result of a decrease in the number of ______ (cell type) and _____ fibers. What are two clinical signs of this?
Fibroblasts
Collagen
1. Thin skin
2. Vascular prominence
What are some causes of dermal atrophy?
1. Cushing's
2. Starvation
3. Corticosteroids
Dermal ______ develops in response to chronic injury to the epidermis (primarily chronic ulceration). Which way are collagen fibers and capillaries aligned in relation to the skin?
Fibrosis
Collagen fibers are perpendicular to capillaries and to the surface of the skin
What condition develops as a result of dermal fibrosis, in which there is granulation tissue in the place of "normal" tissue? What is this called when there is EXCESSIVE granulation tissue?
Scar
Proud flesh (exhuberant granulation tissue)
_____ is an abnormal protein deposit in the skin as a result of primary abnormality of immunocytes.
Amyloid
Chronic
Amyloid is derived from components of _________ light chains. The deposition is a result of _______ inflammation.
Immunoglobulin
Chronic
AL amyloid is seen in dogs with what condition?
Monoclonal gammophathy
or
Plasma cell tumors
____ is a jelly-like glycoaminoglycan and is a normal component of the dermal ground matrix. It is produced by dermal_____ (cell).
Mucin
Fibroblasts
Mucin readily binds to _____. Excess mucin causes a condition known as ________ and is found in Shar-pei dogs.
Water
Mucinosis
Mucinosis is characterized by an excess amount of _____ between ____ fibers.
Mucin
Collagen
Mucinosis can also result in _____ formation, because of the swelling.
Vesicle
Thickened dermis (because of excess mucin and water) can cause thin, fragile _____, and a decrease in dermal ____ fibers.
Skin
Collagen
Animals with mucinosis (Shar-pei) are likely to develop ____ and ____ infections.
Bacterial (Staph)
Yeast (Malassezia)
_____ is symmetrical swelling of facial skin and it may occur because of hypothyroidism.
Myxedema
What is the deposition of insoluble calcium salts in the tissues?
Calcification (or mineralization)
What are three causes of calcification in the tissues?
1. Dystrophic mineralization
2. Metastatic mineralization
3. Idiopathic mineralization
What endocrinopathy is associated with calcification of tissue?
Cushing's Disease
_____ mineralization (which kind) develops as a result of injury or degeneration of cells.
Dystrophic
Dystrophic mineralization occurs as a result of influx of ____ into injured cells and ____ (inc/dec) tissue pH.
Calcium
Decreased
Calcinosis cutis (secondary to Cushing's disease) is an example of which calcification?
Dystrophic
(feels like grains of sand in the tissue)
_____ mineralization (which kind) results because of abnormal metabolism of calcium, phosphorus, and vitamin D.
Metastatic
Uremia secondary to chronic renal disease is an example of which type of mineralization?
Metastatic
Mineralization of the gastric wall is due to which type of mineralization?
Metastatic
Where does mineralization of calcium salts start?
Around blood vessels (perivascular)
Calcification because of unknown causes is known as _________.
Idiopathic
Collagen fibers that are affected with calcification stain what color?
Deep blue
Name one example of idiopathic calcification.
Calcinosis circumscripta
What should you do if an area of tissue is calcified?
You should go in and cut it out
Acute dermatitis involves mainly what two clinical signs?
1. Hyperemia
2. Edema
At the microscopic level, acute dermatitis shows what three things?
1. Leukocytes in affected area
2. Release of cytokines and inflammatory mediators
3. Vasodilation of arterioles and increased blood flow to capillary beds
Why does edema occur with acute dermatitis?
Increased vascular permeability (to let leukocytes out) --> increased leakage of plasma --> edema
Exudate that leaves the skin associated with acute dermatitis is initially _____, and if the insult persists, the exudate contains _____and that means that endothelial damage has occured.
Serous
Blood
Describe the process of leukocytes leaving the bloodstream.
Vasoconstriction --> vascular flow slows --> leukocyte adhesion to endothelium --> migration of neutrophils --> macrophages migrate to inflammation
What are two of the four outcomes of acute dermatitis?
1. Complete resolution (minimal tissue damage)
2. Abscess formation (pyogenic bacteria)
3. Healing w/ scar tissue (significant tissue damage)
4. Chronic dermatitis (stimulus & inflammatory response persist)
Microscopically, with chronic dermatitis you see large numbers of what types of cells? What is it called if a large # of neutrophils are present?
Lymphocytes
Plasma cells
Macrophages

Pyogranulomatous
______ dermatitis is caused by repeated or persistent infections.
Chronic
What are a few causes of chronic dermatitis?
1. Chronic hypersensitivity reactions
2. Presence of granulotamous-inducing organisms (Tb)
3. Presence of foreign body (keratin/hair)
4. Autoimmune disease (continuous response against host antigens [Lupus erythematous])
What is the key cell of the inflammatory response? What cytokine stimulates this cell?
Macrophage
IFN-gamma
What do macrophages secrete to cause tissue damage?
1. Oxygen metabolites
2. Proteases
3. Coagulation factors
4. Growth factors, angiogenesis factors, and collagenases that stimulate fibrosis
What are the three types of dermatitis that were presented in class (not chronic or acute)?
1. Perivascular dermatitis with eosinophils
2. Interface dermatitis with lymphocytes and plasma cells
3. Nodular dermatitis
What is an example of perivascular dermatiis with eosinophils?
Chronic flea bite dermatitis
What is an example of interface dermatiis?
Lupus erythematosus
What is an example of nodular dermatitis?
Equine collagenolytic nodular dermatitis
OR bacterial, fungal, parasitic infections
Describe the histology of equine collagenolytic nodular dermatitis.
Collagen necrosis, accompanied by eosinophilic granulomatous inflammatory response (possibly a hypersensitivity reaction)
_____ is the inflammation of the hair follicle.
Folliculitis
What is furunculosis?
Hair follicule ruptures and spews into dermis - intense inflammatory response
Put these in order from beginning to end:
1. Mural folliculitis
2. Perifolliculitis
3. Furunculosis
4. Luminal folliculitis
2
1
4
3
What are nonspecific changes that are seen early in the development of many types of folliculitis?
Perifolliculitis
Pemphigus foliaceus (a rare group of blistering autoimmune diseases that affect the skin and mucous membranes and destroys desmosomes) causes what type of folliculitis?
Mural folliculitis
Demodex causes what type of folliculitis?
Interface folliculitis
Alopecia areata (immune mediated disease) is associated with what type of folliculitis?
Bulbitis
Bacterial (Staph), fungal (Microsporum) and parasitic (Demodex) infections are associated with what type of folliculitis?
Luminal folliculitis
_____ folliculitis is inflammation in the wall of the hair follicle.
Mural
_____ folliculitis is inflammation in the lumen of the hair follicle.
Luminal
_____ is an inherited autosomal recessive trait in which inflammation initially starts in the ducts and spreads to the glands (sebaceous). It is characterized as an _____ disease, and chronic lesions show complete loss of _____ glands, dermal inflammation, and scarring.
Sebaceous adenitis
____ is inflammation of the apocrine sweat glands. It is closely associated with folliculitis and furunculosis.
Hidradenitis
____ is inflamation of the SQ adipose tissue. Sterile nodular panniculitis is found in the dachshund and miniature poodle.
Panniculitis
Panniculitis may be primary of secondary. _____ develops secondary to petentrating wound or bacterial/fungal dermatitis. _____ develops with diets high in polyunsaturated fats & low in antioxidates (vit E).
Secondary
Primary
____ conditions develop in the fetus and are present at birth.
Congenital
_____ disease are transmitted genetically and may not be manifested at birth but develop later in life.
Hereditary
Ichthyosis can be both inherited and congenital, and the main lesion is _______(thickened skin), and the development of ______(cracks in skin).
Hyperkeratosis
Fissures
What is the defect that causes ichthyosis?
Increased adherance of keratinocytes (prevents normal desquamination)
Ionizing radiation causes damage to what cells?
Dividing cells in the stratum basale
When do lesions develop from ionizing radiation?
2-4 weeks after initial insult
____ burn (degree) has vesicles.
Second degree
_____ burn (degree) is like a sunburn.
First degree
_____ burn (degree) resembles an ulcer (showing of dermis).
Third degree
Ionizing radiation resembles a ____ burn (degree).
Second degree
When does radiation damage to the microvascular system appear?
Months to years after insult
What are three of the five results of ionizing radiation injury to the skin?
1. Leukotrichia (hair pigment loss)
2. Dermal scarring (loss of adnexal structures)
3. Epidermal atrophy
4. Chronic ulceration
5. Squamous cell carcinoma
____ injuries can develop from direct contact or absorption of substnaces from the GI tract.
Chemical
There are two forms of irritant contact dermatitis. Name them.
1. Direct contact (similar to chemical injury)
2. Allergic contact dermatitis (antibodies against antigens?)
Irritant contact dermatitis can be complicated by self-traumitization like _____.
Licking
Scratching
___ ___ reaction occur as a result of an injectible vaccine or therapeutic agent that. It causes an intense ______response and formation of a _______.
Injection site reaction
Inflammatory
Granuloma
Cats injected with certain killed vaccines containing strong adjuvants can result in what strong reactions?
Feline injection site sarcoma
Hepatocutaneous syndrome is also called______.
Superficial necrolytic dermatitis
Superficial necrolytic dermatitis sometimes consists of _____.
Erosions and ulcers with crusts
Idiopathic liver disease, as well as phenobarbital or phenytoid can be the cause of _______.
Hepatocutaneous syndrome (superficial necrolytic dermatitis)
Liver lesions associated with hepatocutaneous syndrome include_____.
Diffuse interlobar fibrosis and collapse of individual hepatic lobules
Pemphigus sp. causes ____ (derm term) to form, and is associated with acantholysis.
Pustules
Acantholysis can cause pustules or ______ to form in the epidermis.
Vesicles
Pustules are located below the stratum _____ in the epidermis.
Corneum
Four etiologies of orthokeratosis
1. Zinc responsive dermatitis
2. Idiopathic seborrhea
3. Vitamin A deficiency
4. Ichthyosis
Two lesions associated with Ichthyosis.
1. Thickened skin (hyperkeratosis)
2. Plates/scales
3. Fissures
Vitamin A definiciency causes what eye problem?
Dry cornea (xerophthalmia)
What are two reasons for Zinc responsive dermatitis?
1. Improper Zn metabolism
2. Zn deficiency (nutrition)
What are a few symptoms of seborrhea?
1. Crusts
2. Grease
3. Scaling
4. Increased production of corneocytes
5. Hyperproliferation of epidermis, hair follicle, sebaceous glands
What causes ichthyosis?
Increased adherence of keratinocytes - it prevents normal desquamination.
Vitamin A deficiency is caused by a lack of ______ in the diet.
B-carotene
What is the morphology of Zn responsive dermatitis?
Superficial necrolytic dermatitis
Scaling
Crusting
Alopecia
Three causes of epidermal atrophy
1. Cushing's
2. Severe malnutrition
3. Localized ischemia
Three causes of spongiosis
1. Staph sp
2. Malessezia sp.
3. Poxvirus
Two causes of acantholysis
1. Pemphigus foliaceus (subcorneal pustules)
2. Pemphigus vulgaris (spinosum from basale)
How do you treat epidermal crusts?
Douse in beta-dine, get crusts off, give penicillin, and give baths often
Dogs with mucinosis are more susceptible to developing _____ (bacteria) or _____ (fungi) infections because of the excessive skin rolls.
Staphylococcus
Malassezia
Dogs with mucinosis develop cutaneous ______.
Vesicles
Mucinosis is characterized as having too much _____ between ____ fibers.
Mucin
Collagen
The cause of myxedema in dogs and humans can be _______.
Hypothyroidism
To treat myxedema, _____ medication should be given in most cases.
Thyroid
When a dog smells uremic, what is your first R/O?
Mineralization (metastatic)
Chronic uremia causes what type of mineralization?
Metastatic calcification
When collagen fibers are damaged, and they accumulate calcium, this disorder is called_____. The affected collagen fibers stain ____ instead of pink.
Idiopathic calcification
Blue
Calcinosis circumscripta (idiopathic calcification) occurs in what three main areas of the body?
Tongue
Foot pads
Boney prominences
Three lesions seen in acute dermatitis
1. Hyperemia (congestion)
2. Pustule
3. Crust
4. Excoriation
5. Epidermal collaratte?
Four causes of chronic dermatitis
1. Chronic hypersensitivity
2. Foreign body
3. Granulomatous-inducing organisms
4. Autoimmune disease (lupus erythematous)
How should you treat dermatitis?
Shave area, let it dry, antibiotic
Chronic proliferative interface dermatitis happens when a normal _____ is faced against an inflammed_____.
Epidermis
Dermis
Three types of dermatitis
1. Perivascular
2. Interface
3. Nodular
Perivascular (acute) dermatitis is usually caused by ______ reaction.
Hypersensitivity
(Contact dermatitis)
Interface dermatisis is usually caused by _____ disease.
Autoimmune
(Lupus erythematosus)
Nodular dermatitis is usually caused by _____. They can be bacterial, fungal, or ______. Nodular dermatitis can also be caused by equine ______ nodular dermatitis.
Infection
Parasitic
Collagenolytic
The etiology of equine collagenolytic nodular dermatitis is ______.
Unknown
=) probably hypersensitivity rxn
Histologically, what does equine collagenolytic nodular dermatitis look like?
Collagen necrosis, and granulomatous inflammatory response
Three causes of congenital defects
1. Nutritional deficiency
2. Virus (poxvirus)
3. Genetic
What is the disorder called when keratinocytes adhere tightly to the epidermis, and fail to shed? What causes this?
Ichthyosis
Genetic disease
What are the two forms of icthyosis that were described in cattle?
Which is fatal?
1. Ichthyosis fetalis - fatal
2. Ichthyosis congenita
What disorder causes sheets of epidermis to be shed from the skin in scales, and skin lesions become thickened and alopecic?
Ichthyosis congenita
Normal hyperkeratosis of the tongue is seen in what neonate?
Foal
What is the disorder characterized by failure of development of hair follicles, and the absence of hair where it is normally present?
Congenital alopecia or atrichia (usually hereditary)
What disorder is characterized by a sparse hair coat, usually accompanied by other congenital defects?
Congenital hereditary hypotrichosis
Congenital hypotrichosis occurs when there are what problems in 1) pigs, 2) calves, 3) sheep & cattle?
1. In utero hog cholera infection
2. In utero BVDV infection
3. Iodine deficiency
A type of hypotrichosis, ____ ____, is characterized by hypotrichosis and hypoplasia of hair follicles, adnexal structures, and teeth.
Ectodermal dysplasia
(all these structures develop from same ectodermal origin)
What disorder causes the skin to be loose and tear easily? What causes this disorder? Depending on type/severity, what other signs can you see?
Collagen dysplasia (collagen fibers are hapharzardly arranged)
Enzyme deficiencies
Abnormal laxity of tendons and joints
What rare disorder can occur in older cats, where the skin becomes extremely thin and fragile? How is it treated?
Feline acquired skin fragility syndrome (FASFS)
Not treatable, attempt to repair usually makes it worse
How does FASFS occur? What diseases is it associated with?
Unknown pathogenesis
Diabetes mellitus
Cushing's
Liver disease (hepatic lipidosis)
Kidney disease
Use of phenytoin or progesterone
What disorder is characterized by the failure of the epithelium, adnexa, oral cavity to completely develop? What is the etiology?
Epitheliogeneisis Imperfecta
(Aplastic cutis)
Heritable condition or spontaneous congenital lesion
What happens when the basement membrane is disrupted?
Can't regenerate epithelium (disrupts epithelial cells in stratum basale)
What is the condition in which there is excessive hair growth and may be congenital or hereditary?
Hypertrichosis
What virus, when infecting lamsb in utero, causes hypertrichosis?
What viruses (in cattle and hogs) is this virus similar to?
Border Disease Virus
(Shaker Lamb Disease)

BVD (cattle)
Hog cholera (pigs)
Hypertrichosis in sheep is also known as _____ lamb disease or _____ lamb disease. Animals with this disease ____ when affected because nervous fibers are _____.
Shaker
Hairy
Shake
Hypomyelinated
Continuous exposure to high temperatures in pregnant ewes can induce in utero ______ in lambs.
Hypertrichosis
"Acral" pertains to what parts of the body?
Legs, toes, ears
____ are lesions caused by self-traumatization (mainly licking).
Acral granulomas
Lesions that occur from acral granulomas include chronic inflammation and ____ dysplasia.
Adnexal
(adenxal structures move deep into dermis where they don't belong)
How do you treat lick (acral) granulomas?
Cut them out (surgical excision)
What is the etiology of lick (acral) granulomas?
Unknown
(possibly peripheral neuritis causing localized sensation)
How can acral (lick) granuloma lead to foreign body invasion and chronic inflammation?
Licking drives keratin and hair deep into dermis - these stimulate foreign body response = chronic immune response
How do you treat a foreign body granuloma, such as a sliver or other plant material?
Cut it out!
Don't just pull it out
What forms in response to a foreign body in the skin?
Granuloma
What are some examples of foreign bodies that can be left in the skin?
Plant material
Suture remains
Penetrating wounds
Ruptured hair follicles (furunculosis)
Keratin/hair particle
What is an example of ACUTE damage to the skin by UV light?
Sunburn
What are three examples of CHRONIC damage to skin by UV light?
Solar dermatitis
Actinic keratosis (or dermatitis)
Neoplasia (squamous cell carcinoma)
Sunlight directly damages _____ (what cell type) and endothelial cells.
Keratinocytes
UV light damages the DNA in keratinocytes by creating ____ dimers between pyrimidine bases.
Thymidine
When UV light makes a thymidine dimer, the damage can be repaired by an _____. But, if a cell undergoes____ before repair, the development of a neoplasia may occur.
Enzyme
Mitosis
UV radiation induces __ cell supressor activity, favoring _____development.
T cell
Neoplasia
Solar dermatitis can cause what to happen to the skin?
Hyperkeratosis (acanthosis)
Epithelial hyperplasia
Dermal fibrosis
Invasion of dermis
What are plaque-like growths that occur from UV light (usually on the nose, ear, lips, or eyelids)? What can these lesions later progress into?
Keratoses
Squamous cell carcinoma
Photo sensitization is different than actinic kerotosis because actinic kerotosis is caused by damage to DNA in keratinocytes, where photosentization is caused by_______.
UV light absobed by molecule in the skin, and this releases energy that produces free O2 radicals. O2 radicals bind to mast cells and cause degranulation and release of inflammatory mediators.
What does photosensitization cause damage to specifically (in the cell)?
Cell membranes, organelles, and nuclei acids in the cell
There are three types of photosensitization. Type one is due to the ingestion of a ______ agent. Give two plant examples.
Photodynamic
(plants are most common source)

Buckweat
Rape
St. John's wart
There are three types of photosensitization. Type two develops secondary to abnormal ____ metabolism which leads to increased tissue and blood levels of _____.
Porphyrin
Who does type two photosensitization generally affect?
Cattle
(shorthorn, ayrshire, holstein)
Photosensitization can be caused by the absorption or ingestion of _____ agents through the skin or the _____ system.
Photodynamic
Circulatory
How is type two photosensitivity caused?
Hereditary
Lack of enzyme to break down uroporphyrin and coproporphyrin in the tissues
Who does type one photosensitivity usually affect?
Herbivores
What are two examples of diseases associated with type two photosensitivity in cattle?
1. Bovine congenital porphyria (pink tooth)
---(also pigs and cats)
2. Bovine erythrocytic photophyria
What is the condition called that affects cattle, in which teeth and bones turn pink, and bones fluoresce under UV light?
Bovine congenital porphyria
Type 3 photosensitivity is also called _____ photosensitization.
Hepatic
Hepatic photosensitization affects the liver by impairing the hepatic secretion of _______(formed from metabolism of chlorophyll).
Phylloerythrin
Who is most likely affected with type 3 photosensitization?
Herbivores
What are some causes of type 3 photosensitization?
1. Primary hepatocellular disease
2. Inherited hepatic defects
3. Bile duct obstruction
4. Toxic plants that cause hepatic disease --> which can lead to photosensitization
The onset of photosensitization after exposure takes only a few ____, and the main signs are cutaneous erythema and ____.
Hours
Edema
________ is a mycotoxin found in rye grase that can cause hepatic damage, and subsequent photosensitization.
Sporidesmin
Sporidesmin causes ____ of biliary epithelium and obstructive ________. This is an example of type 3 photosensitization, so failure to excrete ______ occurs.
Necrosis
Cholangiohepatitis
Phylloerythrin
In sheep that ingest rye grass that is infect with the mycotoxin ______, excessive swelling of the face may occur and is known as "______ ____".
Sporidesmin
"Swelled head"
Ionizing radiation resembles a 2nd degree burn, so ___ may develop within the epidermis, damage to hair follicles results in ______, and damage to sebaceous glands is permanent.
Bullae (vesicles)
Alopecia
Damage to the MICROvasculature, after ionizing radiation, can occur up to ____ ____ after the insult.
One year
Name 3 irritants that can be absorbed by the body and can cause chemical injury.
1. Mercury
2. Thallium
3. Iodine
If you have a reaction to Nickel, you are suffering from an ___ ___ dermatitis.
Allergic contact dermatitis
What is the condition called in which a cat undergoes a reaction to a vaccine and develops a neoplasm?
Feline injection site sarcoma
The rabies virus antigen is found in vessel walls and in follicular epithelial cells. An immune reaction would then cause _____ and ______ (and possible alopecia).
Vasculitis
Folliculitis
Vaccines that cause feline injection site sarcoma are usually_____ (killed/MLV/live) vaccines.
Killed
Feline injection site sarcoma from injections as been associated with the development of a similar condition in dogs. What procedure causes this to develop in dogs?
Microchip implantation
Cats that have been previously vaccinated with FELV and rabies in _____-oil adjuvant have a higher incidence of FISS.
Aluminum
Cats previously inject with long-acting penicillin or methyprednisolone have shown a low incidence of developing _____ after a vaccination.
Feline injection site sarcoma
How do you treat a cat affect with feline injection site sarcoma?
Complete excise the affected area (with big margins)
Name three types of sarcomas seen in feline injection site sarcoma.
1. Fibrosarcoma (usually)
2. Osteosarcoma
3. Histiocytic sarcoma
4. Neurofibrosarcoma
Which vaccine most commonly causes FISS? Second most common?
FeLV
Rabies
Besides getting a vaccine injection, what else helps to cause FISS?
Oncogenes (p53 & c-kit [&mdm-2])
Tumor supressor genes
Certain cereal grains, such as barley and rye, contain the fungus ___ ____, which causes ergot toxicity.
Claviceps purpurea
The fungi, claviceps purpurea, infect the grain head, form _____ (compact fungi), and replace the seed head.
Sclerotia
____ are the toxic principles, most commonly ergotamine and ergonovine.
Alkaloids
How do ergot alkaloids cause lesions?
Dry gangrene
They stimulate adrenergic nerves --> cause prolonged vasoconstriction, ischemia, and thrombosis of small blood vessels and capillaries
What structures of the body are affected when gangrene attacks the body due to ergot toxicity?
Ears, tail, feet
___ foot is similar to ergot toxicity.
Fescue
Fescue foot is caused by ____ that is produced by the infection of certain strains of fescue grass with the fungus _____ ______.
Ergovaline
Neotyphodium coenophialum
Fescue foot can be seen in the winter, when the fungus is found in the dry ___. When pastures are ____ damaged, the incidence increases.
Hay
Frost
____ _____is seen when animals ingest plants with high levels of selenium or an overdose of selenium supplement.
Selenium toxicosis
Selenium toxicosis is sometimes associated with ____ weather.
Dry
How does selenium toxicosis work?
Se replaces Sulfur-containing molecules (which modifies the structure of keratin and other protein
Selenium toxicosis is also called ____ ____ by old-timers.
Alkali disease
What species of animals are most likely affected with selenium toxicosis?
Cattle
Horses
Name three clinical signs of selenium toxicosis.
1. Emaciation
2. Poor quality hair coat
3. Hoof deformities
4. Sloughing of hoof
5. Partial alopecia (tail & mane)
Vetch toxicosis occurs mainly in what two species?
Cattle (Angus & Holstein)
Horses
___ ___ is a legum which is cultivated for pasture, hay, and silage.
Hairy vetch
What are three lesions associated with vetch toxicosis?
1. Dermatitis
2. Conjunctivitis
3. Diarrhea
4. Granulomatous inflammation in many organs (heart in cattle)
How many weeks does it take for clinical signs of vetch toxicosis to appear?
2-4 weeks
What are three clinical signs of vetch toxicosis?
1. Pruritus (itch) --> causes dermatitis and alopecia
2. Diarrhea
3. Emaciation
_____ are epitheliotrophic DNA viruses that affect most mammals and avians. Rarely found in dogs/cats, but ____ virus has been found in cats.
Poxviruses
Parapox (contagious ecthyma)
How do poxviruses cause lesions?
Invade epithelial cells, cause ischemic necrosis by invading vascular endothelial cells, and stimulate DNA replication which results in epithelial hyperplasia
The infection of poxvirus can have a systemic or a localized affected. What is one example of systemic poxvirus? Localized?
Systemic = monkey pox
Localized = swine pox