Clin Med- Dermatology

kelseyfmeyer's version from 2015-11-30 13:37


Question Answer
**what is a primary lesion?initial eruption that occurs due to an underlying disease which occurs spontaneously
**what is a secondary lesion?lesions which evolve from a primary lesion or are caused by some exogenous factor such as the patient or medications
what is a Macule? 1* or 2* lesion? non-raised, circumscribed, area of discoloration that is up to 1cm in diameter. 1* lesion
what is a Patch? similar to macule (non-raised, circumscribed, area of discoloration), but larger than 1 cm. 1* lesion
what is a Papule?solid erythematous (red) elevation in the skin up to 1 cm in diameter. 1* lesion
What is a Plaque?flat-topped elevation in the skin, larger than a papule (papule is up to 1cm, so plaque is >1cm). 1* lesion
what is a Nodule?small, circumscribed elevation >1cm in diameter that extends into dermis or below. 1* lesion
what is a Tumor?mass of varying size that can involve any layer of the skin and/or subcutaneous tissue. 1* lesion
What is a pustule?small, circumscribed elevation within epidermis filled with purulent exudate; often preceded by a papule. 1* lesion
what is a Abscessaccumulation of purulent exudate within dermis or subcutaneous tissue; lesion often fluctuant, but can be firm. 1* lesion
what is a Vesicle?elevation of the epidermis filled with clear fluid that is up to 1 cm in diameter. 1* lesion
what is a Bulla? vesicle(elevation of the epidermis filled with clear fluid) larger than 1 cm in diameter. 1* lesion
what is a Cyst?cavity filled with either fluid or semi-solid material, lined by epithelium. 1* lesion
what is a Wheal?circumscribed, edematous raised lesion. 1* lesion
What is a Epidermal collarette? 1* or 2* lesion?circular ridge of scale that represents the remnants of a pustule, papule, vesicle or bulla that has regressed. 2* lesion
what is a Scar? 1* or 2* lesion?area of fibrous tissue at site of previous trauma or lesion; often alopecic and depigmented. 2* lesion
What is a Erosion? 1* or 2* lesion?superficial lesion within epidermis that does not penetrate into the dermis. 2* lesion
what is a Ulcer? 1* or 2* lesion?deep lesion through epidermis extending into dermis. 2* lesion
What is a Fissure? 1* or 2* lesion?linear lesion (crack) into or through epidermis. 2* lesion
what is Excoriation? 1* or 2* lesion?self-inflicted lesion (scratching, biting, rubbing) causing removal of epidermis. 2* lesion
what is Lichenification? 1* or 2* lesion?thickening and hardening of the skin causing exaggerated skin markings; associated with chronic inflammation or trauma. 2* lesion
what is Hyperkeratosis? 1* or 2* lesion?thickened horny layer of epidermis; ie. callus. 2* lesion
what is a Scale? 1* or 2* lesion?accumulation of cornified cells; can vary in consistency, color & size. Could be 1* or 2*.
what is a Crust? 1* or 2* lesion?composed of dried exudate, blood, serum, scales. Could be 1* or 2*.
what is Alopecia? 1* or 2* lesion?hair loss. Could be 1* or 2*.
what is a Comedo? 1* or 2* lesion?dilated hair follicle filled with cells & sebaceous secretions. Could be 1* or 2*.
what is Hyperpigmentation? 1* or 2* lesion?due to increased melanin within epidermis +/- dermis. Could be 1* or 2*.
what is Hypopigmentation? 1* or 2* lesion?loss of epidermal melanin. Could be 1* or 2*.
**** WATCH VIDEOS FOR DERM DIAGNOSTICSlinks in word document in folder
**which direction should skin scrapings be done in, relative to hair?Skin scrapes should always be performed in the direction of the hair growth
**which direction should skin scrapings be done in, relative to yourself?Skin scrapes are best performed when the scrape is performed in the direction towards yourself (not away from you)

Intro to derm

Question Answer
DAMNIT acronym- D?degenerative, developmental
DAMNNIT acronym- A?anomalous, allergic, auto-immune
DAMNNIT acronym- M?metabolic
DAMNNIT acronym- N?neoplastic, nutritional
DAMNNIT acronym- I?infectious (bacterial, fungal, viral, parasitic), inflammatory, immune-mediated, idiopathic, iatrogenic
DAMNNIT acronym- T?trauma, toxic
what are the three layers of the skin? where is adipose located? where is dense irregular CT located? where are dermal papillae located?epidermis, dermis, hypodermis. Adipose is in the hypodermis, CT is in the dermis, and the dermal papillae are small, nipple-like extensions (or interdigitations) of the dermis into the epidermis.
Primary dermatological lesions can be due to what three things?idiopathic, genetic, endocrine dz (directly associated with whatever dz is goin on)
Secondary dermatological lesions can be due to what two things?exogenous factors, self-inflicted (excoriation)
what 4 primary(or *primary and secondary) lesions are related to color changes?macule, patch, *hyperpigmentation, *hypopigmentation
what is Diascopy, what is it used for and how to you perform it?Diascopy is a way to determine if a reddened area is a macule (local inflammation) or ecchymosis/petechia (bleeding problems). You take a glass side and you press it against the lesion. If it blanches, it is because they BVs are just engorged from inflammation and you were able to push the blood out. If it doesnt blanch, it's because the blood is extravascular, which indicates a bleeding disorder. So diascopy is a test of BLANCHABILILTY
in short words, difference between 1* and 2* lesions?1* is because of a dz. 2* is because of an exogenous factor(tme, sun, etc) or it's self-inflicted
what are 4 raised lesions?papule, plaque, nodule, wheal
with primary lesions, thinkcolor change
coalescing papules form?a flat-topped plaque
vesicles/bulla are often associated with what kinda dz? (not a virus)autoimmune
who can ulcers be a primary lesion on, and what is this called?Sheland sheep dogs, it's called ulcerative dermatosis
what are two things that papules can be associated with?can be associated with mites- demodex and sarcoptes
what are some things that a nodule can contain?inflammatory cells. neoplastic cells. some sort of infiltrate, either inflammatory or neoplastic
what does a wheal indicate?it is a primary manifestation of an allergic reaction
what are four fluctuant lesions?pustule, abscesses, vesicle, bulla
papule--> ____ --> ____ what is this progression?papule-->pustule-->epidermal collarette
what are pustules full of? PURULENT EXUDATE!!! NOT PUSS-- because otherwise you have to describe it as "pussy" lol
who do you see vesicles/bullae more often in, and why?more common in LARGE animals, because they have thicker skin-- in small animals, it forms and usually pops right away
what is the difference between an erosion and an ulcer?an ulcer is when the lesion is through the epidermis and starting into the dermis
If you see Lichenification, what are you thinking?CHRONIC conditions
If you see a epidermic colarette, what do you think it came from?probably either a pustule or a vesicle was here
what are three dzs which might cause there to be comedos?demodex, cushings, primary schnauser comedo syndrome
Crusts (scabs) might be primary to what, and secondary to what?1*- zinc responsive dermatosis (zinc deficient or unable to mobilize it, primary lesions are crusts). 2*- to pustular dz
What does AD, AS and AU stand for?R ear, L ear, both ears
how can hyperpigmentation be 1*? 2*?1*= hyperadrenocortisism. 2*=chronic inflammation
how can hypopigmentation be 1*? 2*?1*= genetic. 2*= acute inflammation
hyper vs hypo pigmentation. which is a result of chronic and which is a result of acute inflamamtion?hyper=chronic hypo=acute
alopecia- can be associated 1* with, 2* with?1*=cushings. 2*=pruritus
what are the two kinds of Seborrhea?seborrhea sica (dry) and seborrhea oliosa (oily)
what is the false neg rate of demodex on skin scrapes?0%!!!! as long as you did the scrape right. The exception is sharpeis though
what is the false neg rate for sarcoptes on skin scrapes?50%!!!! hard to see on a skin scrape (if you see them, can ID because they have really stubby legs)
what does OD, OS, OU stand for?R eye, L eye, both eyes
when describing a lesion, what two big things must you keep in mind?the LOCATION (diffuse/generalized? multifocal? focal?), and the SEVERITY(mild, moderate, severe)
demodex vs sarcoptes---> which is a superficial skin scraping for dx, which is a deep?superficial sarcoptes, deep demodex
how do you know you've properly gone deep enough for a deep skin scrape?you will see capillary bleeding
5 methods for hunting for parasitesskin scraping (deep or superficial), coat brushing, trichogram (hair pluck), tape test, cotton swab with oil
when would you wanna use a deep or superficial skin scrape?MITES! demodex or scabies
what is a trichogram, and what would you wanna use it for?aka hair pluck, you can use this to dx ringworm (fungal infxn), or find lice eggs which are usually cemented onto hairs. You can find demodex attached to hair folicles (rarely find mites on pluck or scrape if healthy animal)
why might you want to use a tape test?might find cheyletiella or a nymph or a tick or sthing
when would you use a cotton swab with oil as a diagnostic tool?put in ear, roll into microscope slide and look for otodectes (ear mites)
If you have done skin scrapes, but can't find demodex, and you SWEAR it's demodex (or it's a sharpei), what can you do?skin biopsy (however, false neg rate with a proper skin scrap is SUPER LOW- should be able to get them)
look at slide 17 for "name that bug" exercisegood to know
*be sure to look over example cases/pictureshelpful
if pawpads are involved, what might you think?autoimmune
whats the little mite that likes the feet?demodex
how would a yeast infection of anywhere usually present?brown/waxy substance with no draining tracts (this appearance would lead you towards yeast more than bacteria)
why can you only use purple stain for impression smears with dogs, but you want the red dye too with cats?because cats have lots of problems concerning EOSINOPHILS, which need the red dye to show up
what are three methods you can use for diagnosing microscopic problems?impression smear, cotton swab, tape test
If you are doing a tape test, what should you avoid using while you process the tape to look at it?avoid the fixative step of the stain- it contains alcohol which ruins the tape's adhesive side
If you think you are going to be looking at yeast, what part of the processing should you avoid?the fixative, which contains alcohol
look at "name that microbe" on slide 20helpful
what is the type of staph which animals get?staph pseudintermedius (NOT aureus, that more for ppl)
which two diagnostic methods can you use for looking at cytology?tape test and impression smear
if you see a bunch of eosinophils, who did this prolly come from?a cat
acantholytic keratinocytes-- when do you usually see these? (look at slide 21 for a pic)usually find in pemphigus folaceaous (autoimmune to desmosomes)
how would you describe ringworm?multifocal alopecia with severe/complete alopecia at each lesion, moving outward over time
what are the three ddx for patchy alopecia?dermatophytosis (ringworm), demodecosis, and superficial pyoderma
If you are trying to get a culture of a dermatophyte, where do you scrape?at the EDGE of the lesion, NOT the center!! the edge is where the active infection is
what are the two fungal culture mediums?DTM (dermatophyte test medium), and Sabaroud’s agar
what are the three major dermatophytes we will be looking at?Trichophyton mentagrophytes, Microsporum canis, Microsporum gypseum
look at slide 23 for pics of the dermatophyteswoohooo
how can you tell the difference between Microsporum canis and Microsporum gypseumgypsum will have less than 6 cells in its structure, canis will have greater than 6 and have thicker walls, as well as have a terminal bud (Canis (dogs) are THICK skinned and can take more than 6 hits, that's why they're our BUDS)
strands of fungi are called?hyphae
Trichophyton mentagrophytes--> what does this look like to identify it?thin walled and rounded ends with more microconidia than macroconidia (more tiny crap)
what does a TVT cell look like?round cell w/vaculoles
one way you know you're looking at an acantholytic keratinocyte?(d.iii.2) Normal keratinocytes lose nucleus as moves up through the diff keratin cell layers as it develops- theses cells have separated too early- still have nucleus (while all the cells around it dont)