skin examination Flashcards
description of gorss examination should include
Number of lesions
Location of lesion
Type of lesion
If parasites found, can it be identified?
what is a scale
a thin accumulation of keratinocytes (keratin cells) flakes
what is a crust
thick accumulation of cells with dried exudate( blood/bus)
what is a macule
a non- palpable (not bumpy) change in skin colour that is <1cm in diameter
what is a papule
a solid elevation of the skin that is <1cm in diameter
what is a pustule
acellular fluid filled lesion (not firm) fluid usually contains neutrophils (type of wbc)
what are the different methods to test for ectoparasites
- coat brushing
-sticky tape preparation
-skin scraping
how to conduct coat brushing and purpose of test
-stand patient over white paper-> brush using flea cmb-> collect any falling scale and cutaneuous debris-> see microscopically with a drop of liquid paraffin
purpose: to look for fur mites, lice and fleas
how to conduct sticky tape preperation and purpose of test
press tape firmly on area and then pull off, repeat several times
Tape to microscope slide
purpose: used to identify mites and malassezia /bac (use diff quick stain) (dip table in stains first then paste on microscope slide)
what does malassezia look like under the microscope (yeast)
like peanuts
purpose of skin scraping
to identify mites investation-> superfical: sarcoptes (fattie bugs)
deep: dermodex (stick)
how to conduct skin scraping
superfical: scrap with scalpel the skin surfave
deep: squiz skin surface-> scrape, little blood (demodex live at the bottom of the hair follicle) tiny flash of blood, we are scraping deep enough
what are the different tests for fungal testing
woods lamp
hair plucking : trichogram and fungal culture
how to conduct woods lamp test and purpose
woods lamp is a fluorence light (blue)
Bright apple green fluorescence along hair shaft (presence of ringworm)
purpose: diagnosing ringworm
note if u dont see anything, does not mean dont have ringworm (limited to microsporum sp- type of ringworm species) and only 50% of microsprum will floresce
Shine light on round lesion (possible ringworm) in a dark room
how to conduct hair plucking test and purpose
trichogram:
pluck hairs with root intact (area with crusting/ scaling) -> place onto slide with KOH- liquid paraffin( clears keratin to see hyphae better) cover with coverslip and loop under microscope
purpose: look for fungal hyphae (attached to hair)
fungal culture (preferred)
put hair on culture, agar prevent the growth of other microbials, phenol red added as ph indicator , gel changes colour ( yellow-> red)
different tests for bacterial/yeast
skin cytology :
sticky tape prep
direct impression smear
swabbing (between toes/ lesions with discharge)
fine needle aspiration (get cells from bump)
what are the two methods to test for skin allergy
intradermal skin testing (preferred)
serum allergy testing (false negatives common)- test kit (blood test)
Where are furmites usually found
Clinging to hair like a kuala
What does cocci look like (bacteria)
Tiny balls
What are the advantages and disadvantages of skin scraping
Adv: easy to perform, cheap, quick
Limitation: face and feet is hard to scrape
False negative is possible (take sample from multiple site, after suspected parasite repeat scrapes after a month of treatment )
How to conduct direct impression smear test for bacterial/ yeast infection
Glass slide is pressed directly onto the surface several times in the same site
Sample is then heat fixed before staining with diff quick stain
Slide is there xamined under a microscope
How to conduct swap test for bacterial or yeast infection
Use cotton swap, swab in ear, skin surface, interdigital spaces, exudative lesions
Sample is rolled onto glass slide
Slide is then heat fixed and stained
Look under microscope
How to desentitise allergy
Given injection or oral dose by owner at home
