Path 1- Integument 4

drraythe's version from 2015-05-03 17:20

Lecture 5

Question Answer
What are the zoonotic pox viruses?Monkeypox, Cowpox, Parapoxvirus
Which Poxviruses are most pathogenic? Who do these 2 viruses affect & how?***Sheeppox & Goatpox (FAD), caused by Capripoxvirus, are the most pathogenic & typically result in systemic infxn w/ mortality in young animals
*What is the pathogenesis of pox viruses?****Proliferation & Necrosis****!!! Viral invasion of epithelium → stimulation of host DNA causes epidermal & dermal Hyperplasia → vascular injury & ischemic necrosis
What is the lesion development of a pox virus?Macule → Papule → Vesicle → Umbilicated pustule → Crust → Scar (MPVUCS)
What is the diagnostic features of Poxviruses?IntraCYTOPLASMIC eosinophilic viral inclusion bodies
3 main types of Herpes inxns mentioned?Dermatotropic, non-dermatotropic & oncogenic
Histological features of Poxviruses?Hyperplasia (proliferation), ballooning degen., necrosis, intracytoplasmic eosinophilic viral inclusion bodies (←Dx!)
Which TYPE of Herpes mainly effects the skin? List the 2 viruses in this category.Dermatotropic Herpesviruses
(1) Bovine Herpesvirus **2** (Ulcerative Mammillitis)
(2) Bovine Herpesvirus **4** (Mammary Pustular Dermatitis)
What are the 4 listed Non-dermatotropic Herpesviruses? Describe this definition.Non-dermatotropic = cutaneous lesions are less common
(1) Bovine Herpesvirus 1 (Bovine Rhinotracheitis, Vulvovaginitis, Balanoposthitis)
(2) Equine Herpesvirus 3 (Coital Exanthema)
(3) Ovine Herpesvirus 2 (Malignant Catarrhal Fever)
(4) Feline Herpesvirus 1 (Feline Rhinotracheitis → ulcerative facial dermatitis & stomatitis)
Which cells does the (Dermatotropic) Herpesvirus infect? Where does it replicate? What does this behavoir cause? Resulting in what?Infects EPITHELIAL CELLS w/ replication in the nucleus → lysis of nucleus → cell death → virus spreads to neighboring cell → MULTIFOCAL tissue necrosis
What does Herpesvirus infxn cause if it infects endothelial cells? Examples of the dzs w/ this?Leads to vasculitis & cutaneous infarction. Examples of this are Ovine Herpesvirus 2 & Alcelaphine Herpesvirus 1 (Malignant Catarrhal Fever)
What is a property/thing that Herpesvirus can do?Can go into LATENCY(torpor)! (W/ inactive virus persisting in tissue such as the Trigeminal Nerve Ganglia)
Malignant Catarrhal Fever is from what type of virus & what kinda damage does it cause?Herpes, vasculitis & cutaneous infarction
*What kinda dermatitis does Herpes cause? Describe the lesion progression**Vesiculo-ulcerative dermatitis**. Lesion progression is: vesicle → ULCER → crusts
What are the histological features of Herpesvirus infxn?Epidermal ballooning & reticular degeneration, lytic necrosis, intranuclear eosinophilic viral inclusion bodies!!!! & few syncytial cells
What are some examples of ONCOGENIC Herpes infections?Guinea pig leukemia, Rabbit lymphoma, Monkey lymphoma & cutaneous tumors
Describe from cutaneous tumors which are caused by oncogenic strains of Herpesvirus? (1) Marek’s dz of chickens (cutaneous follicular lymphoma)
(2) Sea turtle fibropapillomatosis (caused by Herpes-like virus)

(also Kaposi's Sarcoma of hoomans)
In what way(s) is/are papilloma viruses selective?SPECIES & SITE SPECIFIC!
*What kinda lesions do papillomaviruses usually cause?TUMOR FORMATION!!!! USUALLY cause benign tumors (papillomas), but can also cause malignant tumors such as **carcinomas & sarcoids
Explain the pathogenesis (& final result) of a papilloma infxnViral infxn of squamous epithelium → integration into host cell genome → inactivation of tumor suppressor genes (p53 & Rb) → TUMOR FORMATION
Gross lesions of papillomaviruses are ___ & some examples of lesions are?VARIABLE gross lesions! May include benign papillomas (warts), malignant squamous cell carcinoma (less common), plaque-like lesions & sarcoids
In who do benign papillomas occur most frequently in? How might you describe a papilloma?Commonly occur in young animals. Papillomas are exophytic (tending to grow outward beyond the surface epithelium from which it originates), papilliferous (bear papillae) & non-invasive.
Papillomatosis versus papilloma?Papillomatosis = MANY papillomas
Who do sarcoids occur in? Which type of virus does sarcoids fall under? How severe is a sarcoid?Most commonly occur in cats & horses. Associated w/ Bovine Papillomavirus 1 & 2 infxn. They are INVASIVE & DESTRUCTIVE & often will recur after excision.
What is the most common skin tumor of the horse?Sarcoids
Viruses causing cutaneous lesions → Picornavirus cause what dzs?FMD (swine, rumis) & swine vesicular dz
Viruses causing cutaneous lesions → Rhabdovirus cause what dz?Vesicular stomatitis (horse, cow, pig)
Viruses causing cutaneous lesions → Caliciviruses cause what dzs?Vesicular exanthema of swine, feline calicivirus
Viruses causing cutaneous lesions → Parvovirus cause what dz?Porcine Parvovirus
Viruses causing cutaneous lesions → Retrovirus cause what dzs?Feline Leukemia Virus, Feline Immunodeficiency Virus

Lecture 6

Question Answer
Bacterial skin infxns are most commonly caused by?Opportunistic pathogens
What are some portals of entry which bacteria can get in?Pores (hair follicles), hematogenous spread, disruption of the physical barrier, disruption of the immunological barrier
What are 2 ways there might be a disruption of the physical barrier to allow bact to infect skin?(1) Damage to the epidermis (trauma, inflammation)
(2) Disruption of the cutaneous microenvironment & microbiota (causes might be temp/humidity, antimicrobial therapy, bacterial overgrowth & inflammation, such as in allergic & contact dermatitis)
What is dysbiosis?Bacterial overgrowth
What are 2 ways the immunological barrier of the skin might be interrupted to allow a bact infection?Immunosuppression & corticosteroids
*Bacterial skin infxns are most common in WHOM?THE DOG
What are some theories as to why dogs get bacterial skin infxns the most?Poorly understood. Some theories are: relatively thin stratum corneum, ↓ lipid content, poor seal at opening of hair follicles, relatively ↑ pH of canine skin, genetic catastrophe (lots of inbreeding to get breeds)
What is a superficial infxn of the skin called? How about a deep one?Superficial pyoderma & Deep pyoderma (I think I'll have a heart attack and DIE from that suprise)
Canine Superficial Pyoderma is caused by WHAT ORGANISM? What are some possible predisposing factors?Staphylococcus pseudintermedius. Some predisposing factors are trauma, allergy/pruritus. Seborrhea (nonspecific term for CS of scaling, crusting & greasiness), immune deficiency, follicular inflammation or dysfxn, unsanitary conditions
Staphylococcus pseudintermedius causes what?Canine Deep & Superficial Pyoderma
Canine Superficial Pyoderma caused by WHAT??Staphylococcus pseudintermedius
What are the *GROSS LESIONS of CANINE SUPERFICIAL PYODERMA?Erythema, macules, papules, pustules, crusts & **collarettes**
Impetigo → is this a superficial or deep infection? Who does it happen to most frequently? Where does it usually occur?SUPERFICIAL infxn which most commonly affects puppies (& human infants) Less commonly in cows, ewes, does. This occurs on areas of thin hair coat, like abdomen, inguinal, axillary & udder
What type of conditions/situations is Impetigo usually associated w/? How easy it is it get Impetigo? Usually associated w/ unsanitary conditions, abrasions, ↑ moisture, poor nutrition...highly contageous
Which bacteria usually cause Impetigo?It is usually caused by Coag+ Staphylococcus such as S. aureus, S. intermedius, S. pseudintermedius & S. schleiferi
What are the gross lesions of Impetigo? What are the histologic features?Gross: Multifocal pustules & crusts. Histo: *Non-follicular* subcorneal pustules w/ serocellular crusting


Question Answer
Canine Mucocutaneous Pyoderma is it SUPERFICIAL or DEEP? What is the cause of this?SUPERFICIAL infxn, the pathogenesis/cause is unknown but responsiveness to Abx makes them believe there is a bacterial component suspected
Canine Mucocutaneous Pyoderma → Which areas are most affected? Least?Lips & nose are most commonly affected site. Prepuce, vulva, anus are less affected.
Canine Mucocutaneous Pyoderma → What are the gross lesions? What are the histological features?Gross lesions: erythema, swelling, crusting, ulceration, depigmentation. Histologic features: Dense band of lymphoplasmacytic & neutrophilic inflammation at dermo-epidermal junction (lichenoid inflammation), pigmentary incontinence
Exudative Epidermitis of pigs (Greasy Pig Dz) → Superficial or Deep infxn? Severity? What is the etiological agent?SUPERFICIAL infxn which is often fatal in neonatal pigs but is milder in older pigs. Caused by Staphylococcus hyicus (remember my footbal reference? plz don't)
Staphylococcus hyicus causes what?Exudative epidermitis of pigs (Greasy pig dz) (HYIC! the pigskin. football ref? Look I tried)
Exudative epidermitis of pigs (Greasy Pig Dz) → Gross lesions? Histological features?Gross lesions: Thickened, scaly, greasy & exudative skin, especially on face. Histologic features: subcorneal pustular dermatitis & superficial suppurative Folliculitis w/ acanthosis
Dermatophilosis → Aka? Superficial or deep infection? Happens most commonly to who & when?Aka “Rain Rot”, “Rain Scald”. SUPERFICIAL infxn which occurs most often in horses, cattle & sheep in WET weather.
Dermatophilosis is caused by? (describe causative agent & what it does)Caused by Dermatophilus congolensis. G+ filamentous bacteria colonize the superficial epidermis & hair follicle. Bacteria have “railroad-like” appearance
Dermatophilus congolensis causes?Dermatophilosis/Rain Rot/Rain Scald (it rains alot in the Congo)
Dermatophilosis gross lesions are? Histologic features?Gross lesions: papules, pustules & thick crusts that coalesce w/ matted wool or hair. Histologic features: suppurative epidermitis w/ Hyperkeratosis & multi-laminated pustular crusts w/ characteristic bacteria
Ovine Fleece Rot → Superficial or deep infection? Usually associated w/ what? Causative agent?SUPERFICIAL pyoderma which is typically associated w/ wet weather → excessive moisture penetrates the fleece & causes proliferation of Pseudomonas sp.
Pseudomonas sp. are involved in which pyoderma?Ovine Fleece Rot
What are the CS/results of Ovine Fleece Rot? What does fleece rot predispose the sheep to?Acute superficial suppurative dermatitis w/ discoloration of the fleece & rotten odor. Malodor & weakened skin can predispose to myiasis (fly strike)
Myiasis (fly strike) is predisposed by?Ovine Fleece Rot


Question Answer
Deep pyoderma is an infxn of what stuff in the skin?Hair follicle, dermis & subcutis
Which is more common-- deep or superficial pyoderma?Superficial is more common
Deep pyoderma occurs most commonly in who & most commonly involves which bacteria?DOGS, Staphylococcus pseudintermedius
Staphylococcus pseudintermedius usually associated w/?Deep pyodermas (& superficial!)
Bacterial Folliculitis & furunculosis (explain the diff b/t the 2 & their relation)Deep bacterial infxn of the hair follicle (folliculitis) will often lead to follicular distension & rupture (furunculosis)
Furunculosis leads to what?Release of hair shaft, bacteria & keratin debris that causes, severe, localized deep dermatitis → **Infxn & foreign body-type inflammation.
Folliculitis & Furunculosis most often occur in who? Where? Predisposing factors?Most common in DOGS & frequently occurs on pressure points & on the feet, especially interdigital spaces. Dogs w/ allergy, follicular dysplasia, cornification disorders, dermatophytosis, or demodicosis are predisposed. (In HORSES, lesions develop most commonly in association w/ tack (saddle sores), tail & caudal pastern (greasy heel, scratches) )
Subcutaneous abscessation → define this. Who is this most common in? Why?Localized accumulations of purulent exudate (pus) w/in the dermis & subcutis. Common in *CATS due to ↑ frequency of puncture wounds w/ subsequent bacterial infection. (Other causes include foreign body, injxns, shearing & clipping wounds)
How does a subcutaneous abscess usually heal?Typically develop draining tracts & heal by scarring
Cellulitis → What is it? What causes it & what happens?Poorly demarcated area of bacterial infection. Suppurative inflammation of the dermis, subcutis & underlying muscle. Source of infxn usually a penetrating wound or other injury
Necrotizing Fasciitis → happens in who? How common? What is it? What causes it? Aka? How severe is this?DOGS & humans. A RARE & SEVERE form of cellulitis (suppurative inflammation). Most often caused by Streptococcus canis infxn (Strep. pyogenes in humans) aka Flesh-Eating-Bacteria Syndrome. Life threatening condition due to concurrent septic shock
*Life threatening condition due to concurrent septic shock →
*Streptococcus canis usually associated w/?Necrotizing Fasciitis (Dog bit me & the CANINE went into the FASCIA)
(No real pics of this one, I don't want to scar u for life, but if u want to scar urself mentally for the remaider of ur existance, by all means google this! Its ewy-gooey-disgusting fun! Just dont say I didn't warn u!)
Mycobacterial organisms usually live where, who persist by doing what?Intracellular bacteria that persist by surviving inside macrophages by preventing the fusion of phagosomes & lysosomes
*How do you identify mycobacteria?~ACID FAST STAINS such as Ziehl-Neelsen stain & Fite-Faraco stain
Obligate intracellular pathogens (mycobacterium) cause ___ & ___ & are transmitted ___Tuberculosis & Leprosy, transmitted horizontally