9- Use of dermatological diagnostic tests- cytology, scrapes, plucks, biopsies Flashcards
Give 2 reasons why you would biopsy the skin
To establish a definitive diagnosis that cannot be reached by other, less invasive, testing methods
rule out certain conditions
What are the 2 main tests that are carried out on skin biopsies
Histopathology- assess tissue structure
Tissue culture- identifies bacteria/fungi
Do skin biopsies require sedation
Yes- in calm animals sedation/ local is enough
GA is used in all animals feet, pinnae, lips and nose
How to decide what to sample when look at derm patient
sample fully developed primary lesions where possible, avoiding traumatised skin/ necrotic crust
multiple samples (min 3)
aim to sample a representative range of lesions - take multiple samples
In an area of alopecia from what area should you take a sample
across the margin of the alopceia area
area of maximum hair loss
normal haired skin
In an area of ulcerated skin where should you sample
skin just adjacent to the ulcer, where the epidermis is still intact
T/F crusts should be removed before a biopsy is taken
False- do not disturb- send off crusts if disturbed accidentally
In an area of pustules, vesicles or bullae where do you sample
remove whole lesion without disruption (wedge biopsy best)
T/F when taking the skin you need to prep/scrub the skin
False- will get rid of the bacteria/ crust- DO NOT do unless performing a excisional biopsy of nodule
Name the 2 types of wedge biopsies and describe how they differ
Excisional- entire lesion is removed
Incisional- transition from normal to lesion skin (portion)
How should a skin biopsy be handled
by subcutaneous tissue only- not by dermis or epidermis
How long do you need to withdraw antibiotics for before performing a bacterial/ fungal tissue culture
5-7 days
