Derm 1: hx, exam, lesions, dx techniques Flashcards
what is the difference between a primary and secondary lesion?
primary: direct manifestation of a disease process
secondary: lesions that evolve from a primary lesion
some lesions can be both primary and secondary
what is a macule? is it primary or secondary?
flat area of colour change <1cm diameter
primary
what is a papule? is it primary or secondary?
circumscribed elevated lesion <1cm diameter
primary
what is a patch? is it primary or secondary?
flat area of colour change >1cm diameter
primary
what is a pustule? is it primary or secondary?
circumscribed elevated lesion filled with pus
primary
what is a plaque? is it primary or secondary?
flat-topped, raised skin lesion >1cm diameter
idk it actually doesn’t say in the notes
what is a vesicle? is it primary or secondary?
thin-walled fluid filled lesion <1cm diameter
primary
what is a bulla? is it primary or secondary?
thin walled fluid filled lesion >1cm diameter
primary
what is a nodule? is it primary or secondary?
solid mass >1cm diameter
primary
what is a wheal? is it primary or secondary?
flat, firm, raised, emematous lesion; larger and coalescing wheals create angioedema (basically, they’re hives)
primary
what is a cyst? is it primary or secondary?
epithelial lined cavity containing fluid, cellular, follicular, or sebaceous debris
primary
what is alopecia? is it primary or secondary?
aka hypotrichosis
decreased amount of hair/fur
can be both primary or secondary
what is a scale? is it primary or secondary?
fragments of surface epithelium
can be both primary or secondary
what is a crust? is it primary or secondary?
accumulation of cellular debris (pus, blood, keratinocytes)
can be primary or secondary
what is a follicular cast? is it primary or secondary?
keratinous debris adhered to proximal hair shaft
can be primary or secondary
what is a comedone? is it primary or secondary?
dilated and plugged hair follicles
can be primary or secondary
what is hypopigmentation? is it primary or secondary?
decreased epidermal melanin
can be primary or secondary
what is hyperpigmentation? is it primary or secondary?
increased epidermal melanin
can be primary or secondary
what is eukoderma? is it primary or secondary?
white skin
can be primary or secondary
what is leukotrichia? is it primary or secondary?
white fur
can be primary or secondary
what is melanoderma? is it primary or secondary?
dark skin
can be primary or secondary
what is melanotrichia? is it primary or secondary?
dark dur
can be primary or secondary
what is an epidermal collarette? is it primary or secondary?
circular alopecic lesion with peripheral scale and develops from ruptured pustule or bulla
secondary
what is a scar? is it primary or secondary?
fibrous tissue that has taken the place of dermis and subcutis
secondary
what is excoriation? is it primary or secondary?
erosion or ulcerations from self-trauma
secondary
what is erosion? is it primary or secondary?
partial thickness epidermal defect (not to level of dermis)
secondary
what is an ulcer? is it primary or secondary?
full thickness epidermal defect (to level of dermis)
secondary
what is lichenification? is it primary or secondary?
thickened, elephant-like skin, usually also hyper pigmented
secondary
what is a callus? is it primary or secondary?
hyperplastic, thickened, alopecic lesions typically on pressure points
secondary
What is this lesion? What are the top ddx?
erythema (reddening of skin)
ddx are anything that can cause inflammation
top ones: allergic inflammation, yeast dermatitis (malasseziasis), bacterial overgrowth
what is this lesion? what are the top ddx?
hypopigmentation
immune-mediated (DLE), vitiligo, uveodermatologic syndrome, cutaneous lymphoma, post-inflammatory, senile
what is this lesion? what are the top ddx?
hyperpigmentation
post-inflammatory hyperpigmentation, lentigo, melanoma, viral plaques, endocrine dz, senile
what is this lesion? what are the top ddx?
leukotrichia
vitiligo, alopecia areata, uveodermatologic syndrome, post-inflammatory, endocrinopathies, senile
what is this lesion? what are the top ddx?
papules
allergic dermatitis, bacterial folliculitis, demodicosis, dermatophytosis, parasitic, actinic disease, drug reaction, immune-mediated disease (pemphigus - early in disease)
what is this lesion? what are the top ddx?
pustules
bacterial pyoderma, ectoparasites (demodicosis, scabies), pemphigus foliaceus, pustular dermatophytosis, sterile eosinophilic pustulosis, pustular drug eruption, impetigo, sub corneal pustular dermatosis, pyoderma gangrenosum
what is this lesion? what are the top ddx?
plaques
infectious dermatoses (pyoderma, dermatophytosis), eosinophilic plaques (feline), calcinosis cutis, viral plaques, solar disease, neoplastic conditions, sterile granuloma/pyogranuloma syndrome, sterile panniculitis
what is this lesion? what are the top ddx?
vesicle/bulla
bullus pemphigoid, systemic lupus, vesicular cutaneous lupus, drug reaction, contact dermatitis, junctional epidermolysis bullosa, epidermal bulls acquista, mucous membrane pemphigoid, mucinosis
what is this lesion? what are the top ddx?
nodule
deep pyoderma, demodicosis, dermatophytosis, nocardiosis, mycobacterial disease, actinomyces, deep fungal infections, sterile nodular penniculitis, sterile granuloma/pyogranuloma syndrome, histiocytic disease, lupus disorders, neoplasia, nodular dermatofibrosis, follicular cysts, calcinosis cutis
what is this lesion? what are the top ddx?
wheal, hives, urticaria (all mean the same thing) + angioedema
usually an acute allergic reaction
what is this lesion? what are the top ddx?
alopecia
most inflammatory dermatologic diseases can cause hair loss in association with other lesions. non-inflammatory alopecia describes alopecia without other inflammatory lesions where the main clinical finding is the hair loss
top ddx for non-inflammatory alopecia: hyperadrenocorticism, hypothyroidism, sex hormone disorders, alopecia aerate, recurrent flank alopecia, follicular dysplasia, color dilution alopecia, injection reaction, pattern baldness, allergies (cats), anlagen and telogen defluxion, post-clipping alopecia, traction alopecia
what is this lesion? what are the top ddx?
crusts
pyoderma, secondary to any pruritic disease (ex. allergies), demodicosis, scabies, pemphigus foliaceus, seborrhoea, superficial necrolytic dermatitis, Zn-responsible dermatosis
what is this lesion? what are the top ddx?
Scales
seborrhoea, ichthyosis, scabies, cutaneous lymphoma, nearly any form of inflammation
what is this lesion? what are the top ddx?
comedones
chin acne, demodicosis, ringworm, encrinopathies, Sphynx cats, hairless dogs, Schnauzer comedones syndrome, seborrheic conditions
what is this lesion? what are the top ddx?
lichenification
assoc with chronic inflammation and trauma
what is this lesion? what are the top ddx?
calluses
caused by repeated skin trauma at a pressure point
what is this lesion? what are the top ddx?
follicular casts
sebaceous identities, vit A responsive dermatitis, seborrhoea, demodicosis, dermatophytosis
what is this lesion? what are the top ddx?
erosion/ulceration
so many things lmao, he doesn’t list them in the notes so im not gonna bother learning them all
what is this lesion? what are the top ddx?
epidermal collarette
pyoderma, impetigo, pemphigus folieaceus, demodicosis, dermatophytosis
what is this lesion? what are the top ddx?
excoriation
self-induced secondary to prutitis (literally scratches). consider all pruritic conditions
differentials based on body location: nasal planum
discoid lupus erythematous, mucocutaneous pyoderma, pemphigus erythematous, pemphigus foliaceus, uveodermatologic syndrome, vitiligo, cutaneous lymphoma, squamous cell carcinoma (esp in cats), idiopathic nasodigital hyperkeratosis, parasympathetic nose
differentials based on body location: muzzle
demodicosis, dermatophytosis, pemphigus foliaceous, allergic disease, canine eosinophilic furunculosis, feline mosquito bite hypersensitivity, DLE, cutaneous lymphoma, squamous cell carcinoma
differentials based on body location: pinnae
scabies, vasculitis, pineal margin seborrhoea, insect bite dermatitis (esp mosquito bite hypersensitivity in cats), atopy, Zn-responsive, sebaceous adenitis
differentials based on body location: perioral and periocular
atopy, Zn-responsive dermatosis, mucocutaneous pyoderma, feline rodent ulcer, infections (Staph, Malassezia), pemphigus foliaceus, mucocutaneous lupus, DLE, cutaneous lymphoma, SCC
differentials based on body location: paw pad (crusting/hyperkeratosis)
pemphigus foliaceus, leishmania, cutaneous lymphoma, benign hyperkeratotic conditions, Zn-responsive dermatosis, plasma cell pododermatitis in cats, hookworm dermatitis, hepatocutaneous syndrome
differentials based on body location: interdigital
canine atopic dermatitis, canine food allergy, pedal furunculosis, foreign bodies, yeast dermatitis, interdigital cysts
differentials based on body location: face in cats
feline atopic skin syndrome, feline food allergy, D. gatoi, flea allergy dermatitis, herpes viral dermatitis, pemphigus foliaceus, eosinophilic granuloma complex, mosquito bite hypersensitivity, SCC, Bowens disease
differentials based on body location: dorsum
pyoderma, flea allergy dermatitis, pediculosis, cheyletiellosis, sebaceous adenines, pemphigus foliaceus
what is diascopy?
a slide is pressed over an erythematous lesion and is observed for blanching.
blanching is due to vascular engorgement and in most inflammatory processes
non-blanching indicates hemorrhage into the skin and can indicate more serious diseases
what is Nikolsky sign?
pressure is applied to a vesicular lesion or at the edge of an erosive or ulcerative lesion. it is possible if the outer layers of the skin are easily pushed away and can indicate pemphigus vulgaris, sub epidermal blistering diseases, toxic epidermal necrolysis/Stevens Johnson syndrome, and erythema multiforme
what does a positive Wood’s lamp test mean?
dermatophytosis
What organism is this?
Microsporum canis (dermatophyte)
fluffy, white, raised, cottony
What organism is this?
Microsporum gypseum (dermatophyte)
flat, cream to tan, granular
What organism is this?
Trichophyton mentagrophytes (dermatophyte)
white to cream, powdery or cottony
What organism is this?
Microsporum canis (dermatophyte) macroconidia
abundant, pindle shaped, knobbed, thick cells, more than 6 cells ± microconidia
What organism is this?
Microsporum gypseum (dermatophyte) macroconidia
spindle, thin walls, rounded ends, less than 6 cells ± microconidia
What organism is this?
Trichophyton mentagrophytes (dermatophyte)
hardest to find, cigar shaped, thin walled, narrow attachment to hyphae, spiral hyphae, globose clusters of microconidia
true or false: bacterial C&S is used to diagnose bacterial infection
FALSE!! it is taken from pyoderma lesions to identify the causative bacteria and determine what Abx it is sensitive to
What organism is this?
yeast
What organism is this?
not well stained yeast lmao
What organism is this?
cocci
if on skin, most often will be Staph pseudintermedius
What organism is this?
rods
if rods, then culture
What organism is this?
dermatophytosis
What organism is this?
environmental mold spores
what is this?
eosinophilic plaque
eosinophils have arrows, macrophages have arroewheads
what is this?
mast cells
intense granulation!
what is this?
soft tissue sarcoma
what is this?
pemphigus foliaceus
“fried egg cells” = pathognomonic (aka acantholytic keratinocytes)
what is this?
cutaneous lymphoma
what is this?
sebocytes
What organism is this?
Demotex canis (mite)
only in dogs!
What organism is this?
Demodex injai
only in dogs!
What organism is this?
Demodex gatoi
only in cats!
