Derm Final exam

What stage is the hair actively growing

anagen

What stage is hair growing to resting?

catagen

What stage is the resting phase? the vast majority

telogen

What stage is active shedding?

exogen

What systemic factors affect hair growth?

• genetics

• environment

• general health

• hormones

What local factors affect hair growth?

• cytokines

• growth factors

• hormones

What are stimulators of hair growth?

• thyroid

• melatonin

• growth hormone

• androgens

What are inhibitors of hair growth?

• cortisol

• estrogen

• progesterone

• prolactin

Clinical Signs of inflammation

• papules, pustules, and crusts

• epidermal collarettes

• lichenification

• erythema

• excoriations

• salivary staining

• patchy and moth-eaten appearance

Clinical signs associated with non-inflammatory alopecia

• smooth

• well-demarcated

• possible marked hyperpigmentation

• symmetrical

Diagnostics of alopecia

• flea comb

• dermatology database (cat - fecal float)

• DTM culture or PCR

• basic laboratory work

• endocrine function test

• biopsy and histopathology

What 3 breeds lack everything below the infundibulum?

1. Chinese Crested Dog

2. peruvian Inca Orchid Dog

3. Xoloitzcuintli

What is hairlessness also associated with?

dentention defects ranging from partial adontia ot malformation and malposition

The American Hairless Terrier

• autosomal recessive

• born with soft, sparse hair

• lost during first several months

• though to be accelerated follicular cycling

Hairless considerations

• comedone prevention

• solar protection

  • UVA protection

    • dermoscent and epi-pet

  • dog UV suits

Cornish Rex

lack primary hairs, have downy secondary hairs

bent or twisted whiskers

Devon Rex

secondary hairs, short, curled, broken whiskers, ventral alopecia

Sphynx

nearly complete alopecia

hair on digits, tail and muzzle can be prominent

Preauricular alopecia in cats

natural thinning of hair in the area between the eyes and earss

When is preauricular alopecia seen in cats?

1.5 - 2 years of age

Who is preauricular alopecia in cats seen in?

most noticeable in short-haired, dark-colored cats

Tail Gland Hyperplasia

• benign condition

• overactive glandular area

• alopecia, comedones, keratosebaceous debris and thickened skin

• more common in male dogs

• verify no hormonal dysfunction

X-linked Alopecia

• lack hair follicle units

  • frontotemporal, sacral, abdomen, and limbs

• loss of glands

  • skin and airways — secondary infections

• dentition abnormalities

Ventral-type of canine pattern alopecai

• progressive beginning around 6 months of age

• along neck, chest, and abdomen

• dachshunds, chihuahuas, min pins, whippets, boston terriers, and boxer

Pinnal-type canine pattern alopecia

• confined to back of pinna

• beginning at 6-9 months of age

• dachshunds - most commonly

• yorkshire terrier and maltese similar

the cause of color dilution alopecia (CDA) and black hair follicular dysplasia (BHFD)

• not fully understood

• abnormal size, shape and distribution of melanin granules within the hair shaft leads to fracture

• possible defect in melanosome transport mechanisms

• proposed that hair cycle arrest is a conseqeunce of abnormal melanin release

What are color dilution alopecia and black hair follicular dysplasia predisposed?

pyoderma

What breeds are affected by color dilution alopecia and black hair follicular dysplasia?

• any dilute/fawn/blue/merle coloration

• doberman - classic

• yorkshire terrier

• great danes

• chihuahua

• silver labs

canine dilution Alopecia Treatment

• topical care

• solar protection

• pyoderma prevention

Breeds associated with breed specific acquired alopecia

• chesapeake bay retriever

• curly-coated retriever

• portuguese water dog

• irish water spaniel

What is the presentation of breed specific acquired alopecia?

• onset - 2-5 years of age

• areas affected - flanks, dorsum, rump, and caudal things

• no treatment

location of breed specific alopecia in irish water spaniels?

1. neck

2. tail

What breed is affected by idiopathic bald thigh syndrome?

greyhounds

What is the onset of idiopathic bald thigh syndrome?

2-3 years

progressive

What is the diagnosis of idiopathic bald thigh syndrome?

rule out endocrine disease

biopsy will mimic endocrine disease

What is the treatment of idiopathic bald thigh syndrome?

regrowth of hair has been observed in rare cases after racing career has finished

Breeds affected by canine recurrent flank alopecia?

• boxer - poser child

• english bulldog

• airedale terrier

• schnazuer

age of onset for canine recurrent flank alopecia?

~4 years of age

clinical signs of canine recurrent flank alopecia?

rapid onset of well-demarcated flank alopecia and hyperpigmentation

diagnosis of canine recurrent flank alopecia?

• history

• clinical signs

• exclusion

• biopsy

treatment and prevention of canine recurrent flank alopecia?

• melatonin

• variations on light and laser therapy

What breeds get Alopecia X?

• pomeranians

• alaksan malamutes

• chows

• keeshonds

age of onset for alopecia x?

1-3 years of age

clinical signs of alopecia x?

symmetric alopecia and hyperpigmentation sparing the head and limbs

diagnosis of alopecia x?

exclusion

alopecia x - treatment?

• benign observation

• neutering

• melatonin

• microtrauma/microneedling - dr. b choice

what not to try as a treatment with alopecia x?

hormone therapy

MOA of melatonin treatment?

• not completely understood

• work on follicle or centrally altering feedback loop

What is the proposed dosage of melatonin treatment?

• 3-6 mg per dog PO q8-12 hours

• 1-1.3 mg/kg PO q12 hours

What happens when you increase the dark with photoperiod?

• increase melatonin

• increase T4

• increase TSH

• decrease prolactin

What happens when you increase light with photoperiod?

• decrease melatonin

• decrease T4

• decrease TSH

• increase prolactin

clinical signs of hypothyroidism

• dull, dry, brittle hair

• symmetric alopecia

• bridge of nose and tail

• pyoderma and otitis

• facial myxedema

cause of hypothyroidism

primary hypothyroidism

diagnosis of hypothyroidism

• tT4

• fT4 by ED

• TSH

• TgAA

What are the clinical signs of Cushing’s?

• generalized alopecia

• thin skin

• comedones

• calcinosis cutis

• pyoderma

what is the cause of cushing’s?

pituitary or adrenal tumor

diagnosis of cushing’s

• LDDS

• ACTH stimulation

clinical signs of hyperestrogenism

• alopecia of abdomen

• thighs and perineal regions

• linear preputial dermatosis

• ferminization

causes of hyperestrogenism

• ovarian cysts/tumor

• diethylstillbesterol administration

• testicular tumors

• accidental hormone exposure

diagnosis of hyperestrogenism

• signalment

• history

• clinical signs

• serum estradiol

CBC of hypothyroidism

normocytic, normochromic, nonregenerative anemia

Serum chemistries of hypothyroidism

• hypercholesterolemia

• hypertriglyceridemia

• ALT and CK elevations

urinalysis of hypothyroidism

normal

CBC of cushing’s

• leukocytosis

• neutrophilia

• lymphopenia

• eosinopenia

• thrombocytosis

serum chemistries of cushing’s

elevated ALP ± ALT

UA of cushing’s

• low specific gravity

• bacteriruia

• elevated UCCR ratio

What disease is this?

preauricular alopecia in cats

What disease is this?

tail gland hyperplasia

What disease is this?

x-linked alopecia

what disease is this?

canine pattern alopecia

what diseases are these?

• color dilution alopecia

• black hair follicular dysplasia

what disease is this?

idiopathic bald thigh syndrome

what disease is this?

canine recurrent flank alopecia

what disease is this?

alopecia x

what disease is this?

hypothyroidism

what disease is this?

hyperadrenocorticism - cushing’s disease

what is this?

comedones

what is this?

cutaneous atrophy pyoderma

what is this?

calcinosis cuties

what disease is this?

hyperestrogenism

Is chin pyoderma true infection?

no

What is chin pyoderma also called?

traumatic furunculosis

What happens with chin pyoderm?

short hairs are pushed through the follicles due to “life style”

What is the diagnosis for chin pyoderma?

• signalment - usually short-coated dogs

• rule out other differentials

what is the treatment for mild chin pyoderma?

topicals

What is the treatment for moderate to severe chin pyoderma?

systemics ± glucocorticoids

What is the treatment for refractory chin pyoderma?

adhesive tape stripping

what is the diagnosis for eosinophilic folliculitis and furnculosis?

• cytology - eosinophils

• biopsy

What is the treatment for eosinophilic folliculitis and furunculosis?

• 2° infections

• steroids (pred.)

Syndrome I - Zn deficiency - keratinization disorder

defective intestinal absorption

siberian husky and alaskan malamute

syndrome II Zn deficiency - keratinization disorder

rapidly growing puppies or diet issues

diagnosis of Zn deficiency

• rule out other differentials

• biopsy

• response to therapy

treatment for Zn deficiency

• address secondary infections

• zinc supplementation with fatty acids

• possible glucocorticoids

what breeds are dermatomyositis commonly seen in?

• collies

• shetland sheep dogs

dermatomyositis

• inherited disorder

• unknown etiology, but vasculopathy proposed

• symptoms at 2-6 months

• severity is variable even with littermates

• non - pruritic

diagnosis for dermatomyositis

• signalment

• histopathology

• electromyography

treatment for dermatomyositis

• avoid trauma

• pentoxifylline - a staple

• vitamin E and fatty acids

• cyclosporine, glucocorticoids, or JAK inhibitors

what is the staple drug for dermatomyositis? what is the drug of choice?

• pentoxifylline

• cyclosporine

what breed is the poster child for Ichthyosis?

Golder retrievers

What is ichthyosis?

congenital disorder of keratinization