Module 1 MiniModule 6: Diagnostic Tests and Techniques Flashcards
What are the types of scrapes?
- Superficial
- Deep
List the ways to collect skin cytology:
- Tape
- Surface
- #10 Blade
- Spatula - Cotton Swab
- Direct Impression
- Fine Needle Aspirate
List the types of cultures:
- Bacterial
- Aerobic
- Anaerobic
- Mycobacterial
- Fungal
A surface mite that instead of residing in the hair follicles, dwells in the keratin layer of the epidermis, causing pruritic and contagious skin disease in cats
Demodex gatoi
Screening – Superficial Skin Scrape (SSS)
List the Surface Mites:
- Sarcoptes
- Notoedres cati
- Demodex gatoi
- Cheyletiella
- Otodectes cynotis
- Trombicula
- Lynxacarus radovsky
(T/F) For Superficial Skin Scrape is better if you cover a small area
False, cover a LARGE surface area
- generally fewer mites
- may need several slides to spread collected material
- perform at multiple sites
(T/F) If the superficial skin scrape is negative it does not R/O disease
True
What type of Scrape is the following describing?
- Indication
- Follicular Parasites
- Demodex spp. (exception D. gatoi)
- Scrape small focal areas
- Pinch skin
- Induce capillary bleeding
- If negative usually RULES OUT disease
(Exception: hyperplastic tissue)
Deep Skin Scrape
Cutaneous & Otic Cytology
In every derm case, what should you ask yourself?
“What infections are present?”
Surface Cytology:
What are some transmissible diseases that may pass from animal to animal without changing the blade?
- FIV, FELV, Papillomavirus
- Rickettsia, Bartonella
What is the following describing?
- #10 blade method
- NO mineral oil
- Smear material on glass slide
- Heat fix and stain
- Diff Quick/ Gram/ Methylene blue
Surface Cytology
Surface Cytology:
What stain are you using for an Acetate Tape Prep?
Basophilic Stain
- Examine under oil immersion (100x objective)
(T/F) A down side to using acetate tape prep is that it picks up TONS of debris which makes interpretation difficult but good for yeast
True
List the lesions for which Impression Smear would work best for:
- Pustules
- Erosions
- Ulcers
- Draining lesions
- Under surface of crusts
- Cut/ exposed surface of nodule
What is a limitation of Cotton Swab?
Low yield if not exudate
(T/F) A fine needle aspirate CAN replace histopathology
False, does not replace histopathology
Culture:
When do you add anaerobic and atypical mycobacterial culture plus fungal future?
If it is a DEEP infection
Culture:
Bacterial will most likely be ___________
Aerobic
Culture:
What culture do you use for Dermatophytes?
Fungal Dermatophyte Test Medium (DTM)
(use Wood lamp)
List the Indications for Bacterial Culture:
- Poor response to antimicrobial therapy
- All chronic deep infections
- Rods found on cytology
- Unresponsive bacterial otitis - Rule out infectious organism if suspect sterile dz
- Sterile punch biopsy procedure
- Use the sterile instrument pack
- Surgically prep the skin & rinse well with saline before biopsy
What type of culture is this?
Deep Skin Culture
(T/F) Do not biopsy ulcerated areas for culture
True
- Sterilize the collection site from saprophytic fungi by gently wiping with 70% alcohol and let dry
- Remove hair and/or scale from the margin of the lesion or nails with sterile hemostats and place either in a sterile collection vial or inoculate into Sabouraud’s dextrose agar
- A yellow-to-red color change in media with concurrent colony growth, typically occurs within 7-10 days
- For fungal identification, collect macroconidia from the colony using adhesive tape, place the tape on a slide with several drops of lactophenol cotton blue, cover slip the sample and examine under 40x
- Best to send out to a lab
This method is from:
Routine Fungal – DTM
Therapeutic Trials:
- Rule out/in the following parasitic diseases
- Flea allergy dermatitis
- Demodex gatoi
- Sarcoptiform mites (scabies, Notoedres, Cheyletiella)
Insecticidal trial
Therapeutic Trials:
- Cutaneous adverse food reaction
Food allergy dietary trial
While doing a therapeutic trial, part of it needs to be performed without the use of what?
- Antipruritics
- Glucocorticoids
- Antihistamines
- Topical therapy
What are the 2 reasons for preforming a skin biopsy?
- For histopathology
- For tissue culture
When do you biopsy for Histopathology?
- Suspect neoplasia
- Ulcerative disease (not ulcerative lesions)**
- Mucosal lesions
- Footpad lesions
- Nodular lesions
- Unknown disease after work-up
- Rule out disease
In biopsy techniques for histopathology, you _______ (do/do not) prep, scrub, or disturb the lesions
do not
(T/F) Grasping the epidermis DAMAGES the epidermal structures
True
List the three ways to take a Histopathology:
- Punch biopsy (most common)
- Wdge biopsy
- Amputation of third phalanx
What do you biopsy for histopathology?
- Acute (new) lesions
- Primary lesions
* Pustules – very transient
* Papules
* Vesicles – very transient
* Petechiae
* Erythematous macules - Entire lesion
- Multiple lesions
- Center of the area of alopecia
What do you NOT biopsy for histopathology?
- If secondary infection
- Severely traumatized skin
- Chronic lesions
- Large areas of normal skin
(T/F) Biopsy doesn’t have to include all layers of the skin
False, it does have to include all layers
The development of molecular techniques has resulted in tests that identify:
1. Inherited mutations that lead to inappropriate drug metabolism
2. Mutations that lead to genetic diseases of the hair color, adnexa, skin, and muscle
Tests of Non-Cutaneous Organs
It is used to collect surface cytology
10 blade
