Lecture 3: Integument Parts II Flashcards
On what parts of the body are solar insults most common
Poorly haired, lightly pigmented, thin skin
Acute injury from UVB exposure results in
Sunburn erythema
Chronic injury from UVB results in
Dysplasia progressing to neoplasia
What are common neoplasms associated with UVB injury
- SCC
- Melanoma
- Hemagioma/ hemagiosarcoma
What wrong here, and what are you concerned about
hemagioma, concern for progressing to hemagiosarcoma
Which is normal vs abnormal. What do black arrows indicate in middle and right photo. What do red circles indicate
Left: normal
Middle: hyperplasia and dysplasia- solar dermatosis
Right: black arrow: solar elastosis, red circles: sunburn cells
What is photosensitization
A photodynamic agent in circulation reacts to UV light that results in edema/erythema—> vesicles—> necrosis/ sloughing of skin
What is type 1 photosensitization
Ingestion of photodynamic substance (plants, drugs)
What is type 2 photosensitization
Abnormal porphyrin metabolism. Inherited disease of enzyme deficiency
What is type 3 photosensitization
Most common form, occurs in herbivores with liver disease. Chlorophyll in plants converted to phylloerythrin and is unable to be excreted in the bile, ends up in the blood
Where do lesions from photosensitization occur
Non-pigmented areas exposed to sun
What wrong here? Also the cow had yellow eyes and MM, what does that indicate
photosensitization- specifically type 3- icterus indicates liver pathology
What is the pathogenesis of swelled head or facial eczema in ovine
- Ingestion of saprophytic fungus, Pithomyces chartarum
- Produces sporidesmin mycotoxin
- Liver damage/ bile duct injury
- Bile obstruction
- Type 3 photosensitization
- Sheep with heavy fleece have lesions that develop especially on the face
What wrong
Swelled head or facial eczema of ovine due to ingestion of pithomyces chartarum that produce sporidesmin mycotoxin causing liver damage—> type 3 photosensitization
What are two fungal causes of dry gangrene
- Grain contained with fungus produces ergotamine
- Tall grass contaminated with fungus that produces ergovaline
What is the pathogenesis of dry gangrene due to fungus alkaloids
- Ergotamine and ergovaline produced by fungus
- Stimulates adrenergic nerves
- Ateriolar smooth muscle vasoconstriction
- Ischemic necrosis of hindlegs
What wrong and what is potential cause
dry gangrene cause by fungus that produced ergotamine and ergovaline toxins causing ischemic necrosis—> dry gangrene
What is acral lick dermatitis
Lick granuloma caused by psychogenic dermatitis- repeated chewing and licking induces chronic alopecia and proliferative dermatitis
What is intertrigo
Superficial dermatitis on apposed skin surfaces/ folds
Folds susceptible due to retained moisture and frictional trauma—> bacterial infection
What is the sequence of cutaneous lesions in poxviridae viruses
Macula—> Papule—> vesicle—> umbilicated pustule—> crust—> scar
What is an important mode of transmission for poxviridae viruses
Mechanical vectors- mosquitoes, sucking louse
What is the histo appearance of poxviridae
Intracytoplasmic eosinophilia viral inclusion bodies (Bollinger bodies)
What wrong
Poxviridae virus- swine pox
Dog presented with vesicles/ crusts all over body and histo showed this? What is likely problem and what does the histo show that indicates that. What is asterisk and arrow indicating
Parapoxvirus (poxviridae)
Asterisk: ballooning/ hydropic degeneration
Arrow: bollinger bodies
Papillomaviridae causes benign ___
Benign epithelial proliferation
What does papillomaviridae cause
Squamous papilloma, endophytic papilloma, epidermal pigmented plaques, aural plaques, papillomas, sarcoids, SCC
What are the 3 results that occur with papillomaviridae enters stratum basale
- Latent infection without changes in keratinocytes
- Productive infection with cytopathic changes to keratinocytes (nuclear inclusions)
- Virus integration into host cell genome—>neoplasia and malignant
What wrong, what caused
Sarcoids caused by bovine papillomarvirus
What wrong, what caused
Cutaneous papilloma caused by papillomaviridae
what is morphological dx
Aural plaques
What occurs with a orthoherpesviridae virus
Keratinocyte infection and lysis, vesicles—> ulcers and crusts
What is a differential diagnosis for feline facial puritus
Feline herpesvirus 1
What wrong and what is a differential diagnosis
Feline herpetic facial dermatitis caused by orthoherpesviridae virus- feline herpesvirus 1
What are the portals of entry for bacteria into skin
hematogenous, pores, damaged epidermis
what are the targets for bacteria entering the skin
epidermis, dermis, subcutis, vessels, adnexa
what are the targets for superficial pyoderma
epidermis and follicular infundibulum
T or F: superficial pyoderma heals without scarring and there is no lymph node involvement
true
what is the gross appearance of superficial pyoderma
erythema, alopecia, papules, pustules, crust, epidermal collarettes
what is the histo appearance for superficial pyoderma
intraepidermal pustules, superficial luminal folliculitis, serocellular cysts
what is the etiology/cause of exudative epidermitis (greasy pig disease)
staphylococcus hyicus
what lesions are associated with exudative epidermitis (greasy pig disease)
brown greasy exudate with thick epidermis, scaling, loaded with bacteria
what is the distribution for exudative epidermitis
periocular, pinnae, snout, chin, medial leg, spreads to ventrum
what is the etiology/cause of superficial spreading pyoderma
staphylococcus pseudointermedius
Pig presents with brown crusty material all over body. Histo was taken- what is problem
exudative dermatitis/ greasy pig disease
what is likely problem
superficial pyoderma
what is the target for deep pyoderma
hair follicle, dermis, hypodermis
what is the etiology for deep pyoderma
variety of bacteria that access deep tissue via follicles or penetrating wounds
Staphylococcus most common
what is the gross appearance of deep pyoderma
alopecia, papules, pustules, crusts, epidermal collarettes, hemorrhage, bulla, nodules
what is the histo appearance of deep pyoderma
superficial and deep folliculitis that may progress to furunculosis and scarring
what are some associated lesions for deep pyoderma
draining tracts, regional lymphadentitis
what wrong
deep pyoderma
what is granulomatous dermatitis secondary to
traumatic implantation of low virulent saprophytic bacteria causing persistence regional antigenicity
what type of hypersensitivity reaction is granulomatous dermatitis
type 4
what is the gross appearance of granulomatous dermatitis
nodules that may ulcerate and drain
what is the histo appearance of granulomatous dermatitis
macrophages, neutrophils, giant cells, necrosis, fibroblasts
what are some etiologies of granulomatous dermatitis
mycobacterium (M. Lepramurium), non-filamentous bacteria, nodules of filamentous bacteria, nodules of fungus
cat lesion and histo- what is wrong
granulomatous dermatitis, specifically M. Lepraemurium- feline leprosy
what wrong
Erysipelothrix rhusiopathie
what lesions are associated with E. Rhusiopathie
raised, red-purple diamond lesions
what is pathogenesis of E. Rhusiopathie
dermal embolization—> vasculitis, thrombosis, ischemia
what is a common differential for this presentation
salmonellosis
what lesions are associated with salmonellosis
cyanosis and necrosis of extremities (ears)
what is pathogensis of salmonellosis
endotoxin induced venous thrombosis
what is likely cause
E. Coli, shiga-toxin 2e
what lesions are associated with E. Coli shiga-toxin 2e
SQ edema
what is the pathogenesis of E. Coli shiga-toxin 2e
arteriolar endothelium and tunica media damage (edema dz)
what tick borne disease causes this presentation
Rickettsia Ricketssia
what lesions are associated with R. Ricketssia
erythema, petechiae, necrosis
what is pathogensis of R. Ricketssia
Direct vascular damage, vasculitis
what lesions are associated with streptococcus canis
necrotizing fasciitis
what is the pathogenesis for streptococcus canis
bacterial toxins—> shock
what Is likely cause
bacterial septicemia (staphylococcus or salmonella)
SQ fungus require __ to infect
traumatic implantation
T or F: SQ fungal infections do not spread to regional LN
false
SQ or cutaneous fungal infections: pyogranulomatous and draining tracts
SQ
what is the target of cutaneous fungal infections
keratinized tissue with dermal reaction
what is dermatophytosis
ringworm
T or F: dermatophytosis is zoonotic
true
dermatophytosis invade __
cornified tissue (keratinized tissue, hair shaft)
what are the gross lesions associated with dermatophytosis
alopecia, crusting, hair breakage, hair loss from folliculitis, papules, pustules
what is kerion associated with ringworm
eruptive nodular mass
what is pseudomycetoma associated with ringworm
dermal/SQ granulomas
what is onychomycosis associated with ringworm
discolored, malformed, broken claws
what is histo appearance for dermatophytosis
folliculitis and furunculosis, epidermal hyperplasia, intraocorneal micro abscesses
Lesions from cat, what wrong
dermatophytosis (ringworm)
horse: what wrong
Phythiosis (swamp cancer)
what is causative agent of phythiosis
Pythian insidiosum
what is the causative agent of sporotrichosis
sporothrix schenckii
what does sporotrichosis cause
dermatitis, lymphangitis—> visceral dissemination
based on the cigar shaped organism what is likely cause
Sporothrix schenckii
T or F: sporothrix schenckii is zoonotic
true
what wrong
pigmented fungal infection
what stain is this
Gomori methamine silver (GMS)
what does demodex target
hair follicle
T or F: sarcoptes scabei is zoonotic
true
T or F: notoedres cati is zoonotic
true
where does scabies and notoedres cati target on body
ears, head, neck
where does otodectic mange target on body
external ear canal
where does psoroptic mange target on body
external ear canals, body
where does chorioptes Bovis target on body
lower limbs, perineum, udder, tail, scrotum
what wrong
scabies- sarcoptes scabiei
based on the location, what ectoparasite is involved
chorioptes Bovis
pig presented with crusts all over body. This histo was taken what is likely cause and what diagnostic method is most appropriate to obtain a dx
Cause: scabies- sarcoptes scabiei
Dx test: superficial skin scrape
what wrong, what is seen in lower right picture and what dx method is appropriate to obtain dx
Demodex
Lower right picture: demodex outside hair follicle- furunculosis
Dx test: deep skin scrape
what is pediculosis
infestation of lice
what are mallophaga lice
biting/chewing
what are anaplora lice
blood-sucking
entire life cycle of lice is spent on __
host
haemtopinus suis (lice) vectors what diseases
swinepox, African swine fever, mycoplasma suis
What is the vector for diplyidium caninum cestode
fleas
what is the vector for pox viruses, stephanofilaris, habronema
flies
What wrong
mallophaga lice in chicken
what wrong
Equine cutaneous habronemiasis
what wrong
filiarial dermatitis, specifically stephanofilaria stilesi
filarial dermatitis, onchocera targets where on body
head, neck, medial forelimbs, ventral thorax/abdomen
what are the intermediate hosts for filarial dermatitis
black flies, biting midges, flies
stephanofilaria stilesi has predilection for where on body and causes what
ventral midline- alopecia proliferative, eosinophilic dermatitis
