Final Exam Degeneration & Necrosis Deck 1 Flashcards by Preeti Gulve

What are the 6 pathological processes in a tissue?

Degeneration/Necrosis

Inflammation and Repair

Circulatory Disorders

Disturbances of growth (hypoplasia, neoplasms, congenital)

Deposits and Pigmentations (cellular accumulations)

Biochemical dysfunction

How well did you know this?

Not at all

Perfectly

What are the 7 categories of etiologies of pathogenic processes?

Genetic/inherited

Infectious

Metabolic

Toxicologic

Autoimmune

Idiopathic

Iatrogenic

How well did you know this?

Not at all

Perfectly

T/F:

You know an animal DOES NOT have a circulatory disorder when you see the presence of PAPULES and NODULES

True

How well did you know this?

Not at all

Perfectly

A palpable elevation with clear fluid that is LESS than 1 cm

Vesicle

How well did you know this?

Not at all

Perfectly

A palpable elevation with clear fluid that is MORE than 1 cm

Bulla

How well did you know this?

Not at all

Perfectly

What are 4 things that can cause the formation of a

Vesicle or Bulla?

Autoimmune Dermatoses

Viral Infections

Chemical Irritants

Burns

How well did you know this?

Not at all

Perfectly

Another word for “intercellular edema”

Spongiosis

How well did you know this?

Not at all

Perfectly

What is “acantholysis”?

Disruption of intercellular junctions

How well did you know this?

Not at all

Perfectly

What is another word for “INTRAcellular edema”?

Hydropic degeneration

How well did you know this?

Not at all

Perfectly

The condition of fluid accumulation between cells.

If this becomes severe enough, all cells come apart and vesicles form

Spongiosis

How well did you know this?

Not at all

Perfectly

T/F

VESICLES are very prone to secondary infections

TRUE

How well did you know this?

Not at all

Perfectly

What type of exudate would be seen with

Acantholysis

“disruption of intercellular junctions”?

PUS

An immune mediated process, this will progress to a pustule

How well did you know this?

Not at all

Perfectly

In a _______ vesicle, the stratum corneum forms the roof of the vesicle, as in *Impetigo *or Pemphigus Foliaceous

subcorneal vesicle

How well did you know this?

Not at all

Perfectly

In a ______ vesicle, a portion of the epidermis (stratum spinosum) forms the roof, as in Pemphigus vulgaris

suprabasal vesicle

How well did you know this?

Not at all

Perfectly

In a ______ vesicle, the entire epidermis separates from the dermis and forms the roof, as in Bullous pemphigoid

subepidermal vesicle

How well did you know this?

Not at all

Perfectly

A **pustule **is always indicative of this type of reaction

INFLAMMATORY

How well did you know this?

Not at all

Perfectly

What is the cause of pustules?

Leukocyte infiltration

How well did you know this?

Not at all

Perfectly

Dried exudate, serum, blood, and scale that is adhered to the skin surface is called

CRUST

How well did you know this?

Not at all

Perfectly

A palpable solid elevated mass LESS than 1 cm in diameter

like vesicles but with a solid center

Papules

How well did you know this?

Not at all

Perfectly

What can cause a papule?

Infiltration by inflammatory or neoplastic cells

Epidermal hyperplasia

Deposit of mineral like calcium

How well did you know this?

Not at all

Perfectly

A palpable solid elevated mass GREATER than 1 cm in diameter is called a

Nodule

Deeper than a papule

How well did you know this?

Not at all

Perfectly

When papules coalesce, it is called a

PLAQUE

How well did you know this?

Not at all

Perfectly

A loss of epidermis with exposure of dermis that is secondary to

epidermal necrosis*
inflammation*
infarction*
neoplasia*

Ulcers

How well did you know this?

Not at all

Perfectly

Which is more severe, an ulcer or an erosion?

An ULCER is more severe

Ulcers start out as erosions (partial defect in dermis)

How well did you know this?

Not at all

Perfectly

An accumulation of loose keratinized cells caused by * Disorders of keratinization* * Chronic dermatitis*

SCALE

\_\_\_\_\_\_ is an example of scale, from extra skin from the stratum corneum

_dandruff_

What is an epidermal collarette?

A circular rim of scale that occurs secondary to rupture of a vesicle or papule

Thickening and hardening of the skin caused by ## Footnote * chronic inflammation* * chronic irritation*

Lichenification

T/F Pigmentation can be a side effect of Lichenification

TRUE

What is the difference between a papule and a pustule?

A pustule oozes fluid

T/F: When collecting a skin biopsy you should surgically prep the site, grasp with forceps, and biopsy the center of the lesion

FALSE!! DON'T DO ANY OF THIS!

Degenerative/Necrotic lesions tend to \_\_\_\_\_\_\_ and become inflammation/repair over time

_ULCERATE_

Primary _____ disorders often lead to degeneration/necrosis

_circulatory_

A flock of 300 merino ewes and lambs have *swelling and erythema of the skin*, and have **crust **in poorly wooled areas. Some of the crust has broken off and left ulcers. **The pathological process is likely** **epidermal ____________ or** **\_\_\_\_\_\_\_\_\_\_\_\_\_**

The pathological process is likely epidermal _Degeneration/Necrosis_ or _Inflammatory (infectious)_

A flock of 300 merino ewes and lambs have swelling and erythema of the skin, and have crust in poorly wooled areas. Some of the crust has broken off and left ulcers. ## Footnote **What are your differential diagnoses?**

Photosensitization *Dermatophilus* Viral Infection: *Blue Tongue, Pox (Orf), *or *Vesicular Disease (FMD, VS)*

Culture Cytology Biopsy

Describe the pathogenesis of photosensitization

UV light absorbed by photodynamic chemicals in skin → Free radical damage → Epidermal necrosis of lightly pigmented or sparsely haired areas

**Primary photosensitization (Type 1 Exogenous) **in sheep is caused by

*Plants containing photosensitive chemicals* like **St. Johns Wort** **Lucerne** **Perennial Ryegrass**

**Primary Photosensitization (Type II Intrinsic)** in sheep is caused by

**Porphyria** *an inherited deficiency of **porphyrinogen III cosynthetase*** which leads to a *defect in heme synthesis* and then a *build-up of porphyrins*

**Secondary Photosensitization (Type III Hepatogenous)** in sheep is caused by

**poor hepatic clearance of *Phylloerythrin*** which is a *product of a ruminal chlorophyll transformation*

In **Secondary Photosensitization (Type III Hepatogenous)** which toxins can cause *biliary obstruction*?

Lantadenes (Red Lantan) Steroidal Saponins (Tribulus, Pancium) Sporodesmin (Facial Eczema): *Lolium perenne + Pithomyces chartarum → Sporodesmin toxicosis* Pyrolizidine alkaloids Aflatoxin Phomopsin

What is *cholestasis*?

Any condition in which the flow of bile from the liver stops or slows

Ingestion of toxic alkaloids produced by the fungus ## Footnote *Claviceps purpurea*

Ergot Poisoning

A flock of 300 merino ewes and lambs have swelling and erythema of the skin, and have crust in poorly wooled areas. Some of the crust has broken off and left ulcers. ## Footnote **How was Type III Photosensitization ruled out?**

By doing a **serum test** and analyzing the levels, also using **clinical signs**

Wound contraction is a feature of healing by _____ intention

_second_ intention

Fibrous union is a feature of healing by _____ intention

_first_ intention

If skin is trying to heal by first intention, in 24 hours, it will have formed a \_\_\_\_

_scab_

Chronic (years) of UV light exposure leads to

Solar/Actinic Keratosis

T/F You will never see crusts in Solar Injury

FALSE You WILL see crusts in solar injury

Acute UV light exposure leads to \_\_\_\_\_\_\_

_sunburn_

What is the pathogenesis of a sunburn?

Acute UV light exposure → Erythema → Blistering/Vesicles → Sloughing of necrotic skin

T/F Cytokine production has a role in the pathogenesis of sunburns

TRUE

Epidermal hyperplasia and Dermal fibrosis and elastosis caused by UV light exposure is called

Solar/Actinic Keratosis

In chronic UV light exposure (Solar/Actinic Keratosis) there is an increased risk for \_\_\_\_\_\_\_ due to direct DNA injury and subsequent mutations

_Neoplasia_

In solar dermatitis, when a **comedone** ruptures and releases its follicular contents causing a foreign body inflammatory response and secondary bacterial infection, it is called

**Furunculosis**

Cutaneous Horns are indicative of this epidermal pathogenesis

Solar/Actinic Keratosis

What is a **cutaneous horn**?

Keratoses formed from multiple layers of compacted **stratum corneum**

Solar dermatitis related *infundibular keratinzing acanthoma* is known as

Adnexa

In solar dermatitis, skin is thickened by this process

Acanthosis

Injury to the epidermis, reddened or darkened necrotic epidermis and complete healing are characteristic of ____ degree thermal burns

_1st_ degree

Damage to the epidermis and dermis vesicle formation and some adnexa being preserved allowing epidermal regeneration with some scarring is indicative of a ____ degree thermal burn

_2nd_ degree

When damage to the full thickness of the epidermis and dermis, plus or minus the subcutis, sloughing of necrotic tissue followed by granulation tissue, and scar or life-threatening fluid or protein loss (a portal for sepsis) occurs, it is indicative of a ____ degree thermal burn

_3rd_ degree thermal burn

\_\_\_\_\_ form with thermal 3rd degree burns

_vesicles_

What is the main differential when you suspect a **chemical burn**?

**Contact hypersensitivity dermatitis**

A ______ is simply a discolored spot on the skin

_macule_

The pathogenesis of **Erythema Multiforme** and **Toxic Epidermal Necrolysis** is thought to involve Type ____ Hypersensitivity

Type _4_ Hypersensitivity

**Erythema Multiforme & Toxic Epidermal Necrolysis** are induced via ______ \_\_\_\_\_\_ and feature *widespread coalescing erythematous macules* which eventually turn into *vesicles and ulcers*

_antigenic_ _mimicry_

What is the difference between **Erythema Multiforme** and **Toxic Epidermal Necrolysis**?

* Erythema Multiforme* is Milder with single cell apoptosis * Toxic Epidermal Necrolysis* is Severe with **sheets of apoptotic/necrotic cells**

What are 4 other names for **Superficial Necrolytic Dermatitis**?

* Diabetic dermatopathy* * Hepatocutaneous Syndrome* * Necrolytic Migratory Erythema* * Metabolic Epidermal Necrosis*

T/F **Superficial Necrolytic Dermatitis** is a common disorder in older dogs with Diabetes Mellitus

FALSE it is RARE, but is reported primarily in older dogs with Diabetes mellitus or hepatic dysfunction

Long-term anticonvulsant therapy and rare ingestion of mycotoxins precede this rare disease

**Superficial Necrolytic Dermatitis**

T/F Superficial Necrolytic Dermatitis is more common in cats than dogs

FALSE it is more common in older dogs and RARE in cats

An older dog with Diabetes Mellitus comes in and is exhibiting scales and crusts with ulceration on its mucocutaneous junctions, genitals, ear pinnae, elbows and hock, ventral thorax, and even on its pawpads. Because of these painful ulcers on his pawpads, he is having difficulty walking. ## Footnote **What is your diagnosis?**

Superficial Necrolytic Dermatitis

What is the predominant cell type in the epidermis?

Keratinocytes

Dendritic cells (antigen presenting immune cells) of the skin and mucosa are called

Langerhaan's Cells

These cells contain **birbeck granules**

Langerhaan's Cells

Oval receptor cells found in the skin of vertebrates that have synaptic contacts with somatosensory afferents are called

Merkel's Cells