Alopecia 2

Question 1

Inflammatory alopecia

Answer 1

Demodicosis
Bactieral infection
Dermatophytosis

Question 2

Demodicosis

Answer 2

Caused by mites
Demodex canis, cati, gatoi
Normal skin flora from dam - EXCEPT gatoi
Proliforation of mites —> follicular inflammation = hair falls out spontaneously, predisposes to secondary deep pyoderma

Question 3

Junvile onset for canine demodicosis

Answer 3

Juvenile or adolescent (first 18 months)
Treatment not required for localized form
May become generalized & requires treatment

Question 4

adult onset of canine demodicosis

Answer 4

Develops spontaneously or due to underlying condition
Chronic steroid therapy
Hyperthyroidism
HyperADC
Chemotherapy
Requires treatment**

Question 5

Localized - junvile demodicosis

Answer 5

<4 skin lesions ≤2.5cm
Erythema +/- gray hyperpigmentation
Comedones
Face and front limbs

Question 6

Generalized - adult onset of demodicosis

Answer 6

≥5 skin lesions
+/- deep pyoderma
Furuncles (boils), draining tracts, lymphadopathy, fever, anorexia
Not pruruitc UNLESS - secondary pyoderma, host reaction to mites
Face, feet, dorsal trunk

Question 7

Demodex injai

Answer 7

Long bodied mite species
Mainly in sebaceous glands/ducts
Common in terriers
Greasy coat on dorsal trunk

Question 8

DX for injai

Answer 8

Deep skin scrapings - multiple sites
Trichogram - examine hair
Exudate exam - suppurative lesions
Tape impression + squeezing skin

Question 9

TX for demodicosis

Answer 9

Mitaban - only approved, sedation, hypotension hypothermia
Ivermectin, moxidectin - neutro tox XX in MDR1
Milbemycin oxime - off label
Imidacloprid - off label

Question 10

Prevention for demodicosis

Answer 10

Fluralaner - bravecto - off label
Afoxolaner - nexgard - off label
Sarolaner - simparica - off label
Lotilaner - credelio - off label
1/30d

Question 11

When to stop treatment for demodicosis

Answer 11

Two scrapes - one month apart - both neg
Recurrence is common
“Cure” = one year without recurrence

Question 12

Feline demodicosis

Answer 12

Demodex cati
Follicular mite, 2nd - steroids, FIV, FeLV)
Deep skin scrape
Oral ivermectin

Question 13

Lesion for Demodex cati

Answer 13

Non pruritic alopecia patches
Alopecia, erythema, papules, mild pruritus
Mild scaling, follicular casting

Question 14

Demodex gatoi

Answer 14

Pruritic & contagious mite**
Lives in stratum corneum
Only small might can be found
Superficial skin scrapes, fecal floats
Tx: lime sulfur dip

Question 15

Skin lesions for Demodex gatoi

Answer 15

Pruritus, self induced alopecia, exocoriation, Miliary dermatitis, crusting,

Question 16

Dermatophytosis

Answer 16

Caused by
Microsporum Canis (host —>cat)
Microsporum gypseum (geophilic —> soil)
Trichophyton mentagrophyts (host-> small mammal)

Question 17

Transmission of Dermatophytosis

Answer 17

Direct contact w infected host, fomites, contaminated enviro
Fungal spores are viable for moths
Young, old & immunosuppressed are at high risk

Question 18

Asymptomatic carriers of Dermatophytosis

Answer 18

Cats**

Question 19

lesions of Dermatophytosis

Answer 19

Patches of alopecia + erythema
Lesions can expend centrifugally
Pruritus: varies, depends on hosts immune reaction
Mild scaling or crushing
Focal, multifocal, generalized

Question 20

DX for Dermatophytosis

Answer 20

Woods lamp
Trichogram exam
Fungal culture
PCR

Question 21

Woods lamp

Answer 21

Microsporum canis is the species that will
fluoresce
Hair fluoresce with a green apple color at
their base
Lack of fluorescence does NOT rule out
dermatophytosis
Trichophyton mentagrophytes and
Microsporum gypseum do NOT fluoresce
Requires experience

Question 22

Trichogram exam

Answer 22

May reveal fungal spores and hyphae
Requires experience to recognize them

Question 23

Fungal culture

Answer 23

GOLD STANDARD**
Hair shaft and scales are inoculated onto
dermatophyte test medium (DTM)
A color change from yellow to red within 2-3
weeks indicates positive fungal culture
>97% of M. canis causes color change within
14 days
Saprophytic (non-pathogenic) fungi can also
cause color change, but usually after 4 weeks

Question 24

Importance of ID species in fungal culture

Answer 24

Other DX are not specific
Location & preventative measures need to be specific

Question 25

PCR

Answer 25

Advantage: Easy, results within 1-3 business days Results reported as positive/negative for DNA of Microsporum spp. or Trichophyton spp Method of sampling: hair plucks, skin scrape and brushing of the hair coat with sterile toothbrush

Question 26

Shampoo for Dermatophytosis

Answer 26

Miconazole, ketoconazole, Terbinafine

Question 27

Dilute leave on solutions for Dermatophytosis

Answer 27

Enilconazole - not in US

Question 28

Systemic treatment for Dermatophytosis

Answer 28

Ketoconazole - GI, liver tox Fluconazole - cheap, ex out kidney Itraconazole - expensive Terbinafine - cheap, least ADR Griseofulvin - Myelosuppression

Question 29

Environment treamtnent of Dermatophytosis

Answer 29

Prevents spread of infection to susceptible individuals (animals and human) Prevents false positive DTM and PCR (due to inoculation of spores from the contaminated environment All bedding, brushes, rugs etc should be discarded, or washed in 1:10 to 1:100 dilute chlorine bleach

Question 30

Ischemia alopecia

Answer 30

Cells of lower hair follicles and epidermis rely on diffusion O2 and nutrient from blood vessels in the dermis Disruption of blood supply results in hypoxia of the cells which the vessels supply to Skin lesions will vary and depends on the 1. Location (superficial vs deep) 2. Size of the vessel (large vs small) 3. Degree of disruption (partial vs complete occlusion)

Question 31

Vaccine associated alopecia

Answer 31

Etiology: vaccine-induced, most often rabies Skin lesion: Alopecia at the site of vaccination, hyperpigmentation may be seen Diagnosis: history, biopsy of the center of the alopecic lesion Treatment: none, usually will spontaneously resolve (may recur with future vaccination)

Question 32

Dermatomyositis

Answer 32

Common is collies, Shetland sheepdogs

Question 33

Lesions of Dermatomyositis

Answer 33

alopecia, erosion, ulceration, scarring on face (muzzle and periocular), ears and tail tips

Question 34

Other signs of Dermatomyositis

Answer 34

muscle weakness/atrophy, regurgitation (megaesophagus) Diagnosis: skin biopsies Tx w immunosupprsions

Question 35

Generalized ischemic Dermatopathy

Answer 35

Etiology: unknown Skin lesions: Nearly identical to those of dermatomyositis but more generalized Other signs: lethargy, muscle weakness • Diagnosis: skin biopsies Treatment: cyclosporine (5-10mg/kg/day) +/- immunosuppressive dose of oral steroids, pentoxifylline