Lecture 22 4/22/25 Flashcards by Danika Boltz

What are the characteristics of urticaria?

*rapid onset of nodular eruption caused by edema
*type 1 hypersensitivity to:
-drugs
-protein-containing substances
-insect bites
-pollens
-idiopathic

How well did you know this?

Not at all

Perfectly

What are the clinical signs of urticaria?

-acute onset
-localized or generalized wheals
-often not pruritic
-can coalesce/take on strange shapes

How well did you know this?

Not at all

Perfectly

What are the differential diagnoses for urticaria?

-urticarial vasculitis
-dermatophytosis
-eosinophilic granuloma
-neoplasia
-amyloidosis

How well did you know this?

Not at all

Perfectly

How is urticaria diagnosed?

-acute onset
-appearance
-pitting with digital pressure
-biopsy to rule out vasculitis

How well did you know this?

Not at all

Perfectly

What are the possible treatments for urticaria?

-do nothing
-corticosteroids
-antihistamines (hydroxyzine)
-epinephrine

How well did you know this?

Not at all

Perfectly

How can the underlying cause of urticaria possibly be determined?

-drug history
-food trial
-IDAT

How well did you know this?

Not at all

Perfectly

What are the characteristics of ulcerative lymphangitis?

-caused by Corynebacterium pseudotuberculosis
-infection due to wound contamination
-uncommon

How well did you know this?

Not at all

Perfectly

What are the characteristics of Sporotrichosis?

-saprophytic fungal infection
-Sporothrix schenckii introduced via cutaneous wound
-typically the cutaneolymphatic form in horses

How well did you know this?

Not at all

Perfectly

What are the clinical signs of ulcerative lymphangitis?

-sudden onset of swelling of one leg
-multiple firm nodules that ulcerate and drain
-corded lymphatics
-marked edema and fibrosis

How well did you know this?

Not at all

Perfectly

What are the clinical signs of sporotrichosis?

-subcutaneous nodules along lymphatics; especially on legs
-nodules that ulcerate and drain small amounts of pus
-depressed ulcers following drainage

How well did you know this?

Not at all

Perfectly

How are the lymphatic diseases diagnosed?

-cytology showing pyogranulomatous inflammation and possibly organisms
-histopathology
-bacterial and fungal cultures

How well did you know this?

Not at all

Perfectly

What are the characteristics of classical equine viral papillomatosis?

-caused by equine papilloma viruses
-seen in 1 to 2 year olds
-on muzzle, coronary band, and genitalia
-can spontaneously regress in 1 to 3 months
-must rule out sarcoids; esp. in older horses

How well did you know this?

Not at all

Perfectly

What are the characteristics of aural plaques?

-common dz of inner ear pinna
-caused by a papilloma virus
-black flies can serve as mechanical vector
-must rule out Psoroptes

How well did you know this?

Not at all

Perfectly

What is the clinical presentation of aural plaques?

-one to several white plaques on inner surface of pinna
-keratinous material that can be dislodged to reveal pink non-ulcerated base
-often NO clinical signs

How well did you know this?

Not at all

Perfectly

How are aural plaques diagnosed?

-characteristic clinical appearance
-looking for concurrent issues if pruritic

How well did you know this?

Not at all

Perfectly

How are aural plaques treated?

-do nothing
-topical 0.05% tretinoin
-concealment with dyes and markers
-topical imiquimod

How well did you know this?

Not at all

Perfectly

What are the characteristics of equine genital papillomatosis?

-caused by EcPV2
-seen in older horses
-does not usually regress spontaneously
-can be a precursor to SCC

How well did you know this?

Not at all

Perfectly

What are the important differentials for proliferative/ulcerative mass-like lesions?

-pythiosis
-infectious dz
-habronemiasis
-sarcoid
-exuberant granulation tissue

How well did you know this?

Not at all

Perfectly

What are the characteristics of pythiosis?

-common in gulf coast area
-cutaneous and GI forms
-aquatic “fungus” similar to zygomycosis
-lesions located in ares of water contact
-zoospores show chemotaxis toward damaged plant or animal tissue
-requires warm temps and moisture

How well did you know this?

Not at all

Perfectly

What are the clinical signs of pythiosis?

-large ulcerative proliferative lesions
-in areas of water contact
-may arise at site of previous trauma
-often pruritic
-invades blood vessels
-calcified walled-off lesions; leeches/kunkers

How well did you know this?

Not at all

Perfectly

What are the differential diagnoses for pythiosis?

-habronemiasis
-granulation tissue
-infection
-sarcoid
-SCC
-other neoplasia

How is pythiosis diagnosed?

-cytology showing eosinophilic pyogranulomatous inflammation
-biopsy showing pyogranulomatous inflammation with eosinophils (silver stain)
-culture of leeches
-indirect immunoperoxidase technique
-PCR

What are the characteristics of pythiosis treatment?

-very difficult to treat
-not a true fungus; cannot use antifungals
-early dx and surgery is best
-laser therapy post-op
-vaccine available; best if used early and combined with surgery

what are the characteristics of cutaneous habronemiasis?

-aberrant parasitism when larvae gain access to deeper layers of skin
-fly is intermediate host
-requires previously damaged skin
-hypersensitivity involved in pathogenesis
-recurrence is common once originally infected

What are the clinical signs of cutaneous habronemiasis?

-seasonal occurrence -lesions involving medial canthus of eye, male genitalia, and lower extremities -ulcerated, granulated tissue with small gritty yellow grains -variable pruritus

How is cutaneous habronemiasis diagnosed?

-history -physical -cytology showing eosinophils -biopsy -concurrent lesions for parasite to affect

What is the treatment for cutaneous habronemiasis?

*reduce lesion size -intralesional or systemic corticosteroids *prevent re-infection -endoparasite control -fly control -immediate wound care *kill larvae -invermectin

What are the characteristics of sarcoids?

-most common neoplasia of horses -locally aggressive fibroblastic tumor with epidermal and dermal components -caused by bovine papillomaviruses -runs in families -most common around 3 to 6 years of age -can occur anywhere, especially head -can be a single lesion or multiple

What is an occult/flat sarcoid?

annular area of alopecia with visible scaling

What are the differentials for an occult/flat sarcoid?

-dermatophytosis -dermatophilosis -demodicosis -folliculitis -onchocerciasis -alopecia areata

What are the differentials for a verrucous/warty sarcoid?

-papilloma -squamous cell carcinoma

What are the characteristics of a nodular sarcoid?

-subcutaneous nodules -skin may be normal to thin and alopecic

What are the differentials for a fibroblastic/proud flesh-like sarcoid?

-SCC -exuberant granulation tissue -habronemiasis -infectious granulomas

What are the characteristics of a mixed sarcoid?

-likely a transition between verrucous to fibroblastic -malignant

How are sarcoids diagnosed?

-histopath. (NOT on occult forms) -PCR from swabs or scrapings (esp. occult form)

What are treatment options for sarcoids?

-leave occult and verrucous sarcoids alone -cryosurgery -intratumoral chemo. (5-fluorouracil or cisplatin) -BCG immune stimulant -radiation therapy -autogenous vaccines -blood root extract -laser therapy -aldara/imiquimod

What are the three forms of cutaneous mastocytosis?

-solitary nodules -congenital, multiple nodules -malignant form (least common)

What are the characteristics of melanocytic tumors?

-primarily in gray horses -rare congenital form exists -melanoma if 1 or 2 discrete tumors -melanomatosis if multiple coalescing melanomas -seen on vulva, anus, and tail base -more aggressive in non-gray horses

What are the growth patterns of melanomas?

-slow growth for years -slow growth with sudden rapid growth and metastasis -rapid growth and metastasis from the beginning

What are the treatment options for melanomas?

-ignore them -surgical excision -cryosurgery -cimetidine -melanoma vx

What are the characteristics of atheroma?

-epidermal inclusion cyst of false nostril -can surgically remove or ignore

What are the characteristics of leukoderma?

-"white skin" -acquired localized hypopigmentation -can occur with inflammatory skin dz, physical trauma, or reversible toxic depigmentation

What are the characteristics of vitiligo?

-idiopathic leukoderma -born normal; depigmentation around 1 to 2 years of age -no inflammation -may be permanent, re-pigment, or wax and wane -no treatment

What are the characteristics of leukotrichia?

-"white hair" -acquired from trauma or inflammation -spotted leukotrichia can appear suddenly at any age

What are the characteristics of anagen defluxion?

-generalized loss of coat associated with stress or illness -occurs within 2 days to 1 week of inciting incident -hair regrows normally

What are the characteristics of bullous pemphigoid?

-autoimmune dz -causes subepidermal bullae -seen at oral mucosa and skin -treated with corticosteroids -guarded to poor prognosis

What are the characteristics of ehlers danlos/HERDA?

-group of inherited connective tissue disorders -collagen synthesis defect -hyperextensible, fragile skin -lesions occur in areas of wear; like saddle region -healing characterized by atrophic scars -chief complaint may be hematomas -want to minimize trauma and not breed

How is HERDA diagnosed?

-history -physical -pedigree analysis -DNA testing for affected animals and carriers -histopath.; must take deep samples

What are the characteristics of coronary band dystrophy?

-idiopathic defect of coronary band -all four feet affected bands thickened and may fissue

What are the differentials for coronary band dystrophy?

-chorioptes -dermatophytes -contact dermatitis -dermatophilus -selenium toxicosis -pemphigus foliaceus