Lecture 4: Dermatology II Flashcards
When using flea comb, comb through coat in with the direction of __
hair
how can you differentiate dirt vs flea dirt
smear on wet paper towel and flea dirt will leave red streak
what is diascopy, how do you do it/what looking for
- Press glass slide against skin
- If dilated vessels then skin will blanch (erythema)
- If blood leaked into skin, then will not blanch (petechiae, ecchymoses)
what is Dariers sign/how do
urticarial response caused by pressure on skin
Pressure on skin causes hive response
what do you commonly do dariers test/dariers sign for
horses, urticaria, pigmentosa, MCT
what is nikolskys sign/how do
rotating pressure with a tip of pencil or finger causes epidermal separation
what diseases would likely have nikolskys sign
immune mediated diseases like epidermolysis bullnose
what dermatophyte spp is positive under woods lamp
microsporum can is
t or f: some drugs and ointments may fluoresce under woods lamp= false positive
true
woods lamp is not a definitive dx but good for __
monitoring treatment
what do you clean microscope lenses with
lens paper not kimwipes
use __X with __ for bacteria and yeast evaluation under microscope
100x with oil
how Does KOH prep work/what used for
- Add 1-2 drops of KPH applied to hair pluck or skin scrape followed by cover slip and let sit
- KOH will remove epidermal cells/debris allowing to see dermatophytes more easily
where do you scrape for skin scrape
- Areas of hair loss +/- erythema
- Comedones
- Ear margins and elbows if crust or hair loss
How do you do superficial skin scrape
- Place oil on skin
- Scrape indirection of hair in broad strokes 10-15 times
- Turn wrist upward at end to collect material and oil then place on slide
how do you do deep skin scrape
- Pinch area to be scrapped
- Place oil on skin and scrape in direction of hair until light superficial bleeding occurs
- Turn wrist upward at end to collect material and oil then place on slide
t or f: need stain to look at skin scrapes
false
t or f: leave diaphragm open for best evaluation of skin scapes
false- close for better contrast exposure
What are tape preps good for
- Dry lesions
- Seborrhea
- Folds/greasy neck, face, paws
how do you do tape prep
- Place slide into purple stain (no tape)
- Lay on flat counter and add tape on top of slide
- Press firmly
- Turn over slide press firmly to remove excess stain
what is a trichogram
evaluation of plucked hairs
how do you do trichogram
- Pluck hairs with forceps or fingers
- Place in mineral oil
- Examine under 4x and 10x
what stage of hair growth in 1-2 and what is seen in 3
- Anagen
- Telogen
- Melanin clumping
trichograms are good for evaluating what
dermatophyte infection