Dermatology - Pruritis Flashcards
1
Q
What is the pathogenesis of Flea Bite Allergic Dermatitis?
A
type 1 hypersensitivity reaction
2
Q
What are the clinical signs/findings of Flea Bite Allergic Dermatitis?
A
- lumbo-sacral distribution
- pruritis crusting eruption and secondary erythema
- seborrhea, alopecia, excoriations, pyoderma, hyperpigmentation, and lichenification
- cats: miliary dermatitis
3
Q
How is Flea Bite Allergic Dermatitis diagnosed?
A
- distribution of lesions: lumbo-sacral, tail base, caudo-medial thighs, ventrum, flanks
- presence of fleas or flea dirt
- flea antigen test
- elevated serum flea allergen specific IgE
4
Q
How is Flea Bite Allergic Dermatitis treated?
A
- flea eradication: knock down product, insect growth regulator, and environmental control
- monthly spot-on for dogs
- prednisone for severe pruritis
5
Q
What is the pathogenesis of Atopy/Allergic Dermatitis?
A
- type 1 hypersensitivity reaction
- hypersensitivity to aeroallergens
6
Q
What are the clinical signs/findings of Atopy/Allergic Dermatitis?
A
- pruritis
- distribution: paws, face, distal extremities, elbows, ventrum, otitis externa
- secondary infections common: staph, malassezia, otitis, lick granuloma
7
Q
How is Atopy/Allergic Dermatitis diagnosed?
A
- history and clinical signs
- rule out other causes
- allergy tests (intradermal or serum)
8
Q
How is Atopy/Allergic Dermatitis treated?
A
- allergen specific immunotherapy (hyposensitization)
- symptomatic relief
- allergen avoidance
9
Q
Which drugs show strong evidence for symptomatic relief of Atopy/Allergic Dermatitis?
A
- glucocorticoids
- cyclosporine A
- Oclacitinib
- recombinant canine interferon gamma
10
Q
What is the most common food antigen causing allergies?
A
beef protein
11
Q
What are the common locations of food allergy lesions in the dog and in the cat?
A
dog - muzzle, ears, distal limbs, inter-digital, axillae, groins
cat - head, face, pinnae, neck
12
Q
How are food allergies diagnosed?
A
- positive response to elimination diet is the only definitive diagnosis
- intradermal skin testing (inaccurate)
- ELISA serology
- skin biopsy
13
Q
What are the treatments for food allergies?
A
- change in diet: hypoallergenic, hydrolyzed
- prednisone for pruritis
14
Q
What is the pathogenesis of contact dermatitis?
A
- type 4 hypersensitivity reaction
- cellular injury through macrophages and T lymphocytes
15
Q
What are the clinical signs associated with contact dermatitis?
A
- intensely pruritic lesions
- hyperpigmentation, lichenification
- hairless areas most commonly affected
16
Q
What are the clinical signs associated with Sarcoptes infection?
A
- intensely pruritic
- papules, alopecia, erythema, crusts, excoriations
- areas: hocks, elbows, pinna, ventrum, and chest
- secondary weight loss
17
Q
How is Sarcoptes infection diagnosed?
A
- response to treatment
- fecal float
- difficult to find mite on scraping
18
Q
How is Sarcoptes infection treated?
A
- topical dips (Lime, Amitraz)
- topical spot-on or system (Ivermectin, Selamectin)
- clean all bedding/kennels
- treat all affected and in-contact animals
19
Q
Describe the features of localized demodecosis
A
- young patients
- one to several well-circumscribed erythematous, scaly, non-pruritic areas of alopecia
- < 6 lesions
- face, forelimbs
- often resolves spontaneously
20
Q
Describe the features of generalized demodecosis
A
- animals < 18 months
- lesions are usually coalescing and extensive, often with secondary pyoderma
- > 12 lesions
- immunosuppressive disease
21
Q
How is demodecosis diagnosed?
A
- deep skin scrape
- biopsy and histopathology
22
Q
How is local demodecosis treated?
A
- often resolves spontaneously
- local antiparasitic ointment
- monthly follow-ups
23
Q
How is generalized demodecosis treated?
A
- Amitraz dip/baths
- Ivermectin
- always avoid steroids
24
Q
What are the clinical signs of a Cheyletiella infection?
A
- “walking” dandruff
- scaling
- pruritis is variable
25
How is Cheyletiella diagnosed?
- seen with naked eye on fur
- Acetate tape test
- flea comb under microscope
26
How is Cheyletiella treated?
- treat all in-contact animals and the environment
| - topical (shampoo, spot-ons, dips)
27
What are the clinical signs of a hookworm infection?
- interdigital areas affected
- intensely pruritic
- erythema, alopecia, thickening of skin
28
How is a hookworm infection diagnosed?
fecal float
29
What are the clinical signs associated with chigger infestation?
- Chiggers found around legs, head, and abdomen
- inside the ears in cats
- pruritis, papules, erythema
30
How is a chigger infestation diagnosed?
- skin scrapes
| - red color
31
How is a chigger infestation treated?
- two pyrethrin dips spaced two weeks apart
- topical antiparasitics
- topical or oral prednisolone for the pruritis
32
What are the general clinical signs of pyoderma?
pustules
papules
crusts
33
When is a culture indicated with pyoderma?
- if < 50% improvement after 2 weeks of tx
- new lesions after 2 weeks of tx
- residual lesions at 6 weeks
- intracellular rods on cytology
- history of MRSA/MRSP
34
What are the clinical signs of mucocutaneous pyoderma?
- mucocutaneous swelling, erythema, and crusting
- lips and commisures affected symmetrically
- painful, pruritic
- fissures, depigmentation
35
How is mucocutaneous pyoderma treated?
- clip and clean area
| - topical ab: Mupirocin
36
What are the clinical signs of pyotraumatic dermatitis?
- red, moist, exudative, crusting lesions
| - lesions in areas of primary irritation
37
What is impetigo?
| Who normally gets it?
- bacterial disease caused by Staph spp.
| - young dogs
38
What are the clinical signs of impetigo?
- vesicles/pustules
| - mainly affects ventral hairless areas
39
How is impetigo treated?
- antibacterial shampoos (Chlorhexidine, Benzoyl peroxide)
| - topical antibiotic creams (mupirocin, flucidin)
40
What is superficial pyoderma?
folliculitis caused by Staph pseudointermedius
41
What are the clinical signs of superficial pyoderma?
- pustules with hair shaft protruding from center
- patchy focal alopecia
- epidermal collarettes
- scaling, seborrhea
- hyperpigmentation or excoriations if chronic
42
What is found on cytology of superficial pyoderma?
degenerative neutrophils, phagocytosed cocci, and proteinaecous background
43
What is the treatment for superficial pyoderma?
- antibiotics for 21-28 days, and 1 week past resolution
| - antibacterial shampoo
44
What are the general clinical signs of a deep pyoderma?
- deep, draining tracts
- clusters of ulcers
- necro-hemorrhagic purulent bullae or abscesses
45
Which breeds are predisposed to deep pyoderma?
GSDs and Bull terriers
46
How is deep pyoderma treated?
- topical rinses/shampoos
- topical steroid/antibiotic combinations
- systemic antibiotics (beta-lactam resistant penicillins) for 6-8 weeks
47
Which antibiotics are used as 1st tier empiric therapy?
- 1st gen cephalosporins
- amoxicillin/clavulanic acid
- clindamycin
48
Which antibiotics are used as 2nd tier empiric therapy?
- sulfas
- erythromycin
- lincomycin
- doxycycline
49
Which antibiotics are used as 2nd tier based on C/S results?
- chloramphenicol
- rifampin
- amikacin
50
Which antibiotics are used as 3nd tier based on C/S results?
- fluoroquinolones
| - 3rd gen cephalosporins
51
How is actinomycosis acquired?
infection following trauma or penetrating wounds
52
What are the clinical signs of actinomycosis?
- subcutaneous abscesses, draining tracts
| - exudates (thick, yellow, hemorrhagic, foul smelling)
53
How is actinomycosis diagnosed?
- anaerobic culture
- histopathology
- cytology
54
What is the treatment for actinomycosis?
- surgical debulking
| - long-term antibiotics (penicillin G, erythromycin, clindamycin)
55
How is nocardiosis acquired?
wound contamination, inhalation, or ingestion
56
What are the clinical signs of nocardiosis?
- similar to actinomyces
| - pyothorax
57
How is nocardiosis treated?
- surgical debulking, drainage
| - long term ab: TMS, ampicillin, erythromycin, minocyline
58
What are the clinical signs of opportunistic mycobacteriosis?
- slowly developing, subcutaneous nodules, non-healing abscesses, ulcers, and fistulas
- serosanguineous/purulent exudate
- regional LN enlargement
59
How is opportunistic mycobacteriosis treated?
- wide surgical excision
| - long term ab: clarithromycin, enrofloxacin, doxycycline
60
What is intertrigo?
skin fold pyoderma
61
How is intertrigo treated?
- shampoos, rinses, topical antibiotics
62
What are the clinical signs associated with Malassezia infection?
- pruritis
- rancid odor
- erythema, greasy, scaly plaques
- otitis externa (black wax)
- hair turns red-brown
- chronic: lichenification, hyperpogmentation, hyperkeratosis
63
How is Malassezia infection treated?
- anti-yeast shampoos
- creams, lotions, and sprays
- systemic: Ketoconazole, Itraconazole
64
What is dermatophytosis?
fungal infection of keratinized tissues, claws, hair, and stratum corneum
- Micosporum spp.
- causes a folliculitis
65
Which animals are predisposed to dermatophytosis?
young and/or immunosuppressed
66
What are the clinical signs of dermatophytosis?
- focal alopecic lesions
- circular alopecia with scaling
- pruritis rare
67
How is dermatophytosis diagnosed?
- Wood's Lamp
- hair pluck
- fungal culture
- biopsy
68
How is dermatophytosis treated?
- topical and systemic therapy
- topical: shampoo, ketoconazole
- systemic: Grisofulvin, ketoconazole, itraconazole
69
What is Notoedres cati?
| What are the clinical signs of this infection?
- feline scabies
| - alopecia, wrinkled skin, papular rash and crusts
70
How is Notoedres cati diagnosed?
skin scrapes
71
How is Notoedres cati treated?
- Lime sulfur dip
- Ivermectin Selamectin
- Imidocioprid/Moxidectin
72
What are the clinical signs of fur mites in the cat?
- "salt and pepper" appearance
- hairs epilate easily
- eggs on hairs
73
Which endocrine diseases cause non-pruritic lesions in the cat?
- hyperthyroidism
| - hyperadrenocorticism
74
What are the 3 presentations of eosinophilic granuloma complex?
- indolent ulcer
- eosinophilic plaques
- collagenolytic granuloma
75
Describe the indolent ulcer presentation of eosinophilic granuloma complex
- well-circumscribed, proliferative inflammatory lesions with central dish-shaped ulcer
- upper or lower lip
- non-painful and non-pruritic
76
Describe the eosinophilic plaque presentation of eosinophilic granuloma complex
- well-circumscribed, red-yellow, ulcerate, edematous plaque
| - intensely pruritic
77
Describe the collagenolytic granuloma presentation of eosinophilic granuloma complex
- well-circumscribed, linear or raised, nodular, firm, yellow-pink lesion
- non-painful, non-pruritic
78
What is the treatment for eosinophilic granuloma complex?
- prednisolone
| - cyclosporine A
79
What is feline acne?
| What is the clinical appearance?
- idiopathic disorder of follicular keratinization
- comedones on chin and lower lip
- papules and pustules
- furunculosis and scaring
80
What is the clinical appearance of feline leprosy?
- chronic draining nodules
| - pus and fluid oozing out of skin
81
What are the possible causes of feline leprosy?
- bacterial or fungal
- panniculitis
- collagenolytic granuloma
- foreign body
- neoplasia
