Patent wth Localized or Generalized Alopecia Flashcards
definition of alopecia
hair loss from areas of the body where it is normally present
Categories of hair loss
decreased hair numbers, hair maturation, hair breakage
Local or generalized
inflamm or non-inflamm
the 3 major causes of localized alopecia
3 major causes of folliculitis which are…
diagnostics that are important with focal or MF hair loss…. Others for maybe more generalized can be
Skin scrapings, cytology, fungal culture, trichography
general CBC, UA, chem
Endocrine testing
How to know if the hair is lost by self-trauma or follicular dysplasia?
tips broken (self) tips tapered (dysplasia)
What is the trichography sensitive to
can detect self-trauma vs. foll dysplasia
can pick up demodex
dermatophytosis
the stage of hair growth
Major differentials for Alopecia (13)
- Folliculitis (bacteria, Demodex, dermatophytes)
- Vaccine-associated ischemic dermatopathy
- familial canine dermatomyositis
- Hyperadrenocort
- hypothyroid
6, Alopecia X - Cyclic Flank Alopecia
- Pattern Baldness
- Color dilution alopecia - other dysplasia
- sertoli cell tumor
- anagen defluxation
- telogen defluxation
- feline asymmetrical alopecia
3 common types of localized folliculitis alopecia. What are others that are always on the differential list?
bacterial (dogs0
demodex (dogs)
dermatophytosis (Cats)
PF
cut lyphoma
Any localized alopecia can…
become generalized
Vx associ. ischemic demratopathy happens in
recently vx (rabies) small breed white fluffies Poodles Bichon Friese
Dx of Vx associ. ischemic demratopathy
FNA
Biopsies
C/S, Hx
R/O demodex
Tx of Vx associ. ischemic demratopathy
Pentoxifylline
Familial Canine Dermatomyositis causes what in whom?
shetlands, collies
hereditary, inflammatory condition of skin and muscles
Autosomal dominant with variable expressivity
When do animals present with Familial Canine Dermatomyositis
6-12 months
Clinical signs of Familial Canine Dermatomyositis
lesions - alopecia, erythema, scaling, mild crusting
marked atrophy of skin**
myositis after skin lesions
high-stepping gait
food in the bowl
atrophy of mast muscles
Dx of Familial Canine Dermatomyositis
C/S and skin biopsies
But do skin scrapings first to r/o demodex
Prognosis of Familial Canine Dermatomyositis
good with only skin
Tx of Familial Canine Dermatomyositis
pentoxifylline
Vitamine E
Cyclosporine
topical tacrolimus
HyperAC Clinical signs
hypotonic skin symmetrical alopecia easy bruising delayed wound healing seborrhea sicca PUPDPG panting pot-bellied muscle wasting
HyperAC Predisposes to…
bacterial infections calcinosus cutis demodex Comedones coat color lightening
HyperAV Dx
biopsy
urine cort:cr
ACTH stim
LDDST
HyperAC Tx
Reduce steroid dose
switch to cyclo, tacrol
mitotane, trilostane (for adrenal tumors)
DMSO
Hypothyroidism clinical signs
epidermal atrophy abnormal keratinization dry, scaly skin hyperpigmented from myxedema no hair growth - stops in anagen phase lightening of the hair rat-tail looking appearance secondary pyoderma
but most will not have cutaneous signs and just have lethargy and weight gain
You will only see pruritis with Hypothyroid if…
pyoderma or bacterial infection is present
Age and breed predilctions to Hypothyroid
6-10 yrs
large or giant breeds
Dx of hypothyroidism
C/S and TH levels Low TH, T4 High TSH non-regenerative normo/normo anemia hypercholesterolemia liver enzyme elevations
Why is the wrong dx and actual euthyroid sick a problem?
give thyroxine which will stimulate hair growth and you will think you got the dx right.
What is the Dx approach to hypothyroid?
recheck TH levels in 2 months
look for improvement of signs
Only keep giving TH when you think the signs are reducing
What do biopsies and histo tell us about hypothyroid?
it will point to endocrine disease but not much further.
Prognosis of hypothyroid
requires lifetime treatment but is really good.
need to ensure levels are high enough
What to watch for as contra-indications in thryoid hormone supplementation?
safe, but watch in dogs with heart disease - see signs in 2 weeks
What to warn owners of with hypothyroid treatments
the alopecia will get worse before it gets better.
Alopecia X/Hair cycle Arrest typically happens in…and wheny
pomeranians, siberian huskies, malamutes, poodles,
before 3 years old
CLinical signs of Alopecia X/Hair cycle Arrest
dull, dry hair coat
loss of primary hairs
looks like a puppy coat
then it turns into alopecia of the trunk, caudal thighs, neck and tail
the alopecic skin can become hyperpigmented, especially in sites of sunburn or trauma
NO pruritus
Dx of Alopecia X/Hair cycle Arrest
r/o cushings and hypothyroid
SKin biopsies**
adrenal sex hormone panel but not useful
Tx of Alopecia X/Hair cycle Arrest
benign neglect
oral melatonin
mitotane and trilostane
but these are considered a little bit harsh for the cosmetic problem.
Color dilution alopecia typically hits
dobermans
Characteristics of the Color dilution alopecia
brittleness and broken hairs by about 6 months of age
Cause of color dilution alopecia
abnormal melatonin deposition into irregulat macromelanosomes –> disrupts the integrity of the hair shafts. this is progressive
This will predispose to bacterial infection
Dx of Color dilution alopecia
r/o the other causes
skin scrapings
trichograms - clumping of melatonin and dysplastic hair shafts
Tx for Color dilution alopecia
avoid mechanical rauma and treat secondary infections
Prognosis of Color dilution alopecia
poor
Feline symmetrical alopecia clinical signs
massive pruritus manifested by excessive grooming which removes hairs
Feline symmetrical alopecia dx
bloodwork/UA to r/o hyperthyroidism and FLUTD
trichogram
Skin scrapings, fungal culture and ectoparasite Tx trials are important
Feline symmetrical alopecia closely resembles but is differentiated by…
looks a lot like endocrine disease but there is the stubble of broken off hairs
DDx for Feline symmetrical alopecia
flea hypersens AD Adverse food reaction dermatophytosis cheyletiella Maybe truly psychogenic
What is anagen and telogen defluxion?
an insult that causes hair shafts to break off suddenly.
How long after does anagen and telogen take after insult/
anagen - days
telogen - 1-3 months
prognosis of defluxion
very good
Canine flank alopecia is characterized by…
seasonal dermatosis
bilaterally symmetrical hair loss
hyperpigmentation
Lesions have scalloped edges
Who gets canine flank alopecia and where
boxers, bulldogs, and airedale terriers
in northern latitudes from the changes in day length
Dx of canine flank alopecia
skin biopsies to find dysplastic keratin filled follicles.
Tx of canine flank alopecia
nothing
some people try melatonin but meh
