Diseases of the Skin p1192-1222 Flashcards by Jennifer Sexton

Chose which autoimmune skin disease this describes: Histologically - intraepidermal acantholysis and immunologically by intercellular deposition of immunoglobulin; antibodies against transmembrane protein desmoglein 1 —> proteolytic enzymes are released that destroy attachments between adjoining epidermal cells; primary lesion is a pustule that is fragile and transient, ruptures soon and results in erosions, collarettes, scale and crust; steroid treatment or azathioprine for treatment

A. Alopecia areata
B. Bulbous pemphigoid
C. Pemphigus foliaceus
D. Pemphigus vulgaris

C. Pemphigus foliaceus

Biopsy submitted - looking for intragranular to subcorneal cleft and vesicle formation

How well did you know this?

Not at all

Perfectly

Chose which autoimmune skin disease this describes: rare disease reported in horses; antibody against epidermal transmembrane protein desmoglein 3; vesicles and ulcerative lesions in mucocutaneous and cutaneous areas

A. Alopecia areata
B. Bulbous pemphigoid
C. Pemphigus foliaceus
D. Pemphigus vulgaris

D. Pemphigus vulgaris

How well did you know this?

Not at all

Perfectly

Chose which autoimmune skin disease this describes: autoimmune vesiculobullous and ulcerative disorder that affects the cutaneous basement membrane zone; anti-BMZ Abs bind to a glycoprotein Ag in the laminate lucida of the BMZ; clinically by painful, crusted or ulcerative lesions of the skin, mucous membranes and mucocutaneous junctions

A. Alopecia areata
B. Bulbous pemphigoid
C. Pemphigus foliaceus
D. Pemphigus vulgaris

B. Bulbous pemphigoid

How well did you know this?

Not at all

Perfectly

Chose which autoimmune skin disease this describes: non pruritic alopecia; most commonly affected the mane, tail and face, although any part of the body could be affected

A. Alopecia areata
B. Bulbous pemphigoid
C. Pemphigus foliaceus
D. Pemphigus vulgaris

A. Alopecia areata

How well did you know this?

Not at all

Perfectly

What is the presumed etiology of atopic dermatitis?

A. Type I hypersensitivity
B. Type II hypersensitivity
C. Type III hypersensitivity
D. Type IV hypersensitivity

A. Type I hypersensitivity, mediated by IgE. IgE is directed toward specific allergens, and when allergens are bound to two IgE antibodies, on the surface of mast cells, the mast cell releases granules containing substances that erythema, vascular leaking and pruritus.

How well did you know this?

Not at all

Perfectly

What’s the difference between urticaria and angioedema?

Urticaria is characterized by transient focal swellings in the skin or mucous membranes called wheals. Angioedema is essentially identical but involves the SQ tissues.

How well did you know this?

Not at all

Perfectly

Describe how milk allergy occurs in dairy cattle.

Increased intramammary pressure causes milk proteins to reach circulation, inciting a Type I hypersensitivity. Seen in cattle fo the Channel Island breeds. CULL!

How well did you know this?

Not at all

Perfectly

What kind of hypersensitivity is contact dermatitis?

A. Type I hypersensitivity
B. Type II hypersensitivity
C. Type III hypersensitivity
D. Type IV hypersensitivity

D. Type IV hypersensitivity - a delayed-type hypersensitivity, so prior exposure is required to sensitize the skin to the material eliciting the dermatitis

How well did you know this?

Not at all

Perfectly

What is the infective stage of Dermatophilus congolensis?

Zoospores released from chronically infected animals that have become moistened, are the source of infection in cases of rain rot.

How well did you know this?

Not at all

Perfectly

What are the three conditions that must be present for Dermatophilus to manifest?

Carrier animal
Moisture
Skin abrasions

How well did you know this?

Not at all

Perfectly

What are the differences between folliculitis, furunculosis and impetigo?

Folliculitis - inflammation of the hair follicles secondary to a bacterial infection
Furunculosis - follicular infection that breaks through the follicular wall
Impetigo - bacterial infection that causes subcorneal pustules but does not involve hair follicles

How well did you know this?

Not at all

Perfectly

What is the bacteria most likely isolated from bacterial folliculitis?

Staphylococcus, both S. aureus and S. pseudointermedius

How well did you know this?

Not at all

Perfectly

What kind of bacteria is associated with cellulitis in equids? Define cellulitis.

Cellulitis - deep suppurative infection that separates the planes of tissues

Coagulase-positive staphylococci has been isolated from all reported cases

How well did you know this?

Not at all

Perfectly

Pigeon fever is attributed to what bacteria? What test is used to diagnose, and does it distinguish between internal and external abscesses?

Pigeon fever is caused by Corynebacterium pseudotuberculosis. The synergistic hemolysis inhibition test is useful for diagnosis of internal abscesses but is unreliable for external abscesses.

How well did you know this?

Not at all

Perfectly

Which viral disease of the skin is described?
In cattle, lesions are seen on the teats, penis, interdigital skin or alimentary tract. In horses, lesion are seen on the face. Rare in goats and sheep. Small lesions can be crushed, pinched or surgically removed. Tissue can be made into a crude autogenous vaccine. The same virus causing these lesions in horses can be isolated in horses.

A. Aural plaques 
B. Bovine herpes mammillitis 
C. Goat and Sheeppox
D. Papilloma virus
E. Pseudocowpox

D. Papilloma virus

How well did you know this?

Not at all

Perfectly

Which viral disease of the skin is described?
Inner pinna is often affected; nonpruritic, can occur on the genitalia and mammary glands; biopsy or shaving off lesion can stimulate reduction or resolution of masses, but can be temporary; may release viral antigens into the blood stream during a surgical procedure

A. Aural plaques 
B. Bovine herpes mammillitis 
C. Goat and Sheeppox
D. Papilloma virus
E. Pseudocowpox

A. Aural plaques, a form of viral papilloma virus

How well did you know this?

Not at all

Perfectly

Which viral disease of the skin is described?
Related to contagious ecthyma of sheep and goats and bovine papular stomatitis; can cause lesions in humans; confined to teats of cattle; causes minor teat lesions —> small papular followed by crusting and circular spread of the lesion —> ring or horseshoe-shaped scab; increased incidence of mastitis; vesiculation is RARE

A. Aural plaques 
B. Bovine herpes mammillitis 
C. Goat and Sheeppox
D. Papilloma virus
E. Pseudocowpox

E. Pseudocowpox

How well did you know this?

Not at all

Perfectly

Which viral disease of the skin is described?
Can causes oral lesions, udder lesions or generalized skin disease; vesicles may appear and others ulcerated immediately; separate cow from herd and milk last

A. Aural plaques 
B. Bovine herpes mammillitis 
C. Goat and Sheeppox
D. Papilloma virus
E. Pseudocowpox

B. Bovine herpes mammillitis, caused by BHV-2

Which viral disease of the skin is described?
Causes pyre is, anorexia, conjunctivitis, rhinitis and skin lesions; attenuated vaccine is a good control method bc the immunity is long lasting; morbidity is high

A. Aural plaques 
B. Bovine herpes mammillitis 
C. Goat and Sheeppox
D. Papilloma virus
E. Pseudocowpox

C. Goatpox and sheeppox

Diseases are similar but sheeppox has more severe systemic signs; capripoxviruses; mortality is higher in sheep than in goats; humans can develop lesions from goat pox

List some fungal disease of the skin in large animals.

Dermatophytosis - Trichophyton or Microsporum
Malassezia - seen in between mammary gland of mares
Sporotrichosis - a zoonotic disease; yeast becomes pathogenic bc of its ability to convert from yeastlike form to mycelia phase
Histoplasmosis - reported in donkeys, “farcy” cause of equine episodic lymphangitis in east Africa
Phaeohyphomycosis
Zygomycosis
Pythiosis - causative agent of swamp cancer; occurs on the limbs, abdomen, neck and lips; dense granulation tissue containing masses of yellow-gray necrotic tissue, sometimes calcified

Pediculosis has several species that belong to two different orders. What are these and how do they differ?

Mallophaga - is the biting louse

Anoplura - the sucking louse

What is treatment for pediculosis?

Ivermectin at 200 ug/kg every 14 days for 2 applications, but only works for sucking lice. Need to use topicals, like pyrethroids, permethrin, selenium sulfide, imidacloprid, phoxim, fipronil

What causes trombiculidiasis?

The larval stage of mites, called “chiggers.” The larvae feed on the host, and releases substances in their saliva that hydrolyzes the epidermis, allowing tissue fluids to be released.

What are the four different types of mites?

Psoroptic
Chorioptic
Sarcoptic
Demodectic

Pick which type of mange is described here: A problem in cattle, but has been eradicated in horses and sheep in the US; hallmark of infestation in all species is pruritus; 2 week life cycle, but can live off of host for up to 3 weeks; Merino sheep are more susceptible; recognized by their round bodies and long, segmented pedicles; recommended that ___ ovis-infested cattle be isolated for a min of 14 days after treatment to prevent transmission to susceptible contact cattle; reportable in the US A. Chorioptic mange B. Demodectic mange C. Psoroptic mange D. Sarcoptic mange

C. Psoroptic mange

Pick which type of mange is described here: Known as leg mange; does not penetrate the epidermis and does not affect humans; common in cattle and sheep, uncommon in goats and variable in horses; life cycle is 2-3 weeks and cannot live off host for more than a few days; variably pruritic; reportable in the US A. Chorioptic mange B. Demodectic mange C. Psoroptic mange D. Sarcoptic mange

A. Chorioptic mange

Pick which type of mange is described here: Uncommon contagious disease of horses, cattle, sheep and goats; burrow into the epidermis and completes life cycle in 10-17 days; can live with a variable survival rate off host; small numbers can cause clinical disease, so negative skin scrapes do not rule out disease; reportable in the US A. Chorioptic mange B. Demodectic mange C. Psoroptic mange D. Sarcoptic mange

D. Sarcoptic mange

Pick which type of mange is described here: Rare; live in hair follicles and sebaceous and sweat glands; host specific; little is known about life cycle; ___ caballi is a normal inhabitant of pilosecbaceous apparatus of the eyelids; ___ equi and is the species that has been associated with disease; goats and cattle develop modular lesions that involve the face, shoulder and neck; mites are elongated and have stubby legs A. Chorioptic mange B. Demodectic mange C. Psoroptic mange D. Sarcoptic mange

B. Demodectic mange

The females of this species feeds on the dorsal or ventral surface of the horse. Alopecia, apples, crusts and erythema may all be present. Evidence suggests a hereditary predisposition to developing a hypersensitivity. Hallmark of disease is pruritus. Therapy consists mainly of controlling the parasite. ``` A. Blow fly strike B. Culicoides hypersensitivity C. Cutaneous habronemiasis D. Cutaneous onchocerciasis E. Hypoderma F. Screwworm G. Stephanofilariasis ```

B. Culicoides hypersensitivity Varying studies have shown an IgG and/or IgE component

This adult fly is 3x the size of a house fly, with females being attracted to fresh wounds. Batches of white eggs are laid on the periphery of the wound. Once hatched, larvae begin to feed, head down, on the exposed tissue. Life cycle is average 21 days; cannot overwinter in cold climates. Wounds become liquefactive necrosis, profuse brown exudate and fetid odor. Control has been achieved through sterilization of males. REPORTABLE. ``` A. Blow fly strike B. Culicoides hypersensitivity C. Cutaneous habronemiasis D. Cutaneous onchocerciasis E. Hypoderma F. Screwworm G. Stephanofilariasis ```

F. Screwworm Cochliomyia hominivorax

Cause serious loss of sheep and wool in many countries. Females are attracted to decaying animal matter. Can overwinter and life cycle is generally complete in 2-4 weeks. Most common site of infection is the breech of sheep. Larvae are dispersed throughout the wound, unlike primary screwworm. ``` A. Blow fly strike B. Culicoides hypersensitivity C. Cutaneous habronemiasis D. Cutaneous onchocerciasis E. Hypoderma F. Screwworm G. Stephanofilariasis ```

A. Blow fly strike - cochliomyia macellaria, Phaenicia sericata, Phormia regina

This is a common filarial dermatitis of the equid. Seen primarily in adult horses, the adult parasite is found in the funicular part of the ligament up nuchae, where calcified nodules are found. The microfilariae migrate to ventral midline, lower eyelid and lateral limbus of the eye. The intermediate hose is Culicoides. Hypersensitization might be caused by Ag released by dying microfilariae ``` A. Blow fly strike B. Culicoides hypersensitivity C. Cutaneous habronemiasis D. Cutaneous onchocerciasis E. Hypoderma F. Screwworm G. Stephanofilariasis ```

D. Cutaneous onchocerciasis - Onchocerca cervicalis

This is a filarial dermatitis of cattle. Transmitted by the female horn fly (Haematobia irritans). Causes a ventral midline dermatitis. No approved treatment, clinical signs are mild. ``` A. Blow fly strike B. Culicoides hypersensitivity C. Cutaneous habronemiasis D. Cutaneous onchocerciasis E. Hypoderma F. Screwworm G. Stephanofilariasis ```

G. Stephanofilariasis

Reported in sheep, goats and humans. Flies are bee like in appearance. Eggs hatch in 3-7 days after which larvae penetrate the skin and migrate. ___ lineatum migrate to sq connective tissue of the esophageal wall where ___ bovis migrate toward the spinal cord. Cysts (warbles) develop around L1 larvae, which is what causes the clinical signs. ``` A. Blow fly strike B. Culicoides hypersensitivity C. Cutaneous habronemiasis D. Cutaneous onchocerciasis E. Hypoderma F. Screwworm G. Stephanofilariasis ```

E. Hypoderma

This is a granulomatous disease caused by deposition of this larvae by flies at wounds or sites of body moisture. L3 larvae are deposited near the mouth then swallowed to mature in the stomach. CANNOT penetrate normal healthy skin. Animals with a dilute hair coat have a predilection for this disease. PCR assay is available, and may allow diagnosis when larvae are not found on biopsy. ``` A. Blow fly strike B. Culicoides hypersensitivity C. Cutaneous habronemiasis D. Cutaneous onchocerciasis E. Hypoderma F. Screwworm G. Stephanofilariasis ```

C. Cutaneous habronemiasis - Habronema muscae, Habronema microstoma, Draschia megastoma

What is the most common bovine ocular tumor and the second most common tumor recognized in the horse?

Squamous cell carcinoma

Other than excision, what are other treatment modalities for SCC?

Cryosurgery, radio frequency hyperthermia, radiation therapy, 5-fluorouracil and intralesional cisplatin; piroxicam was successful in the long-term control in one horse

Equine sarcoids are the most common tumor in equids. What virus is this likely associated with the pathogenesis?

Bovine papilloma virus type 1 and 2; BVP DNA sequences are always found in sarcoids, but have also been found in the skin of normal horses. The role in the etiology of sarcoids is still undetermined.

Why is the infection of BPV in horses, causing sarcoids, considered abortive?

BPV cannot replicate in horses nor be serially passed from BPV-induced fibropapillomas. An alternative theory is that an equine variant of BPV may be the cause of sarcoids.

List the mechanisms of cellular oncogenesis in sarcoids that involve expression of 3 transforming genes: E5, E6 and E7.

E5 - activates platelet-derived growth factor beta receptor to trigger downstream pathways controlling cell survival and proliferation; inhibits MHC class I; inhibit anoikis which allows transformed cells a survival advantage and allows immune evasion E6 and E7 - bind to Rb and p53 proteins, preventing apoptosis and enhancing survival of transformed cells E7 - inhibit anoikis which allows transformed cells a survival advantage and allows immune evasion

T/F Sarcoids are benign lesions because they are slow growing.

F - Sarcoids are a progressive disease that invades and destroys surrounding normal tissue, does not regress spontaneously, and recurs predictably after surgical mass removal

What are the three different types of sarcoids?

Occult - circular area of alopecia, gray scaly surface Verrucous - sessile or pedunculated, thickened skin with dry rough surface Nodular - also called fibroblastic sarcoids, dermal/subcutaneous nodule to large exophytic mass with a skin surface that ultimately ulcerated

What are the different treatments available for sarcoids?

Ablative - surger, laser vaporization, cryotherapy, hyperthermia, caustic ointment Cytotoxic - radiation therapy, chemotherapy Biological - immunotherapy