Chapter 3 - Principles of Diagnosis Flashcards
steps in dermatologic diagnosis (5)
- history
- physical - identify the morphology of basic lesion
- consider clinicopathologic correlations
- configuration or distribution of lesions
- laboratory tests
the most important part of the physical examination is __
inspection
Dermatology is a visual specialty and diagnosis rests heavily on skin inspection
Skin disorders are divided into 2 broad categories:
rashes and growths
a discrete lesion resulting from proliferation of one or more of the skin’s components
growth
an inflammatory process that usually is more widespread than a growth
rash
for a rash, important diagnostic information can be obtained by noting ___
the arrangement of distributed
the initial history can be abbreviated by asking 3 general questions:
how long?
does it itch?
how have you treated it?
most common symptom for skin disorders is ___
itching
__ can cause all types of skin rash
Drugs
in patients with a generalized maculopapular eruption, the two most common causes are __
drugs and viruses
chronic skin ulcer from persistent herpes simplex infection is a sign of ___
immunosuppression - AIDS
__ is the leading cause of workers disability
Industrial dermatiis
A complete “skin exposure history” is required whenever ____ is suspected
contact dermatitis
what are the 3 essential requirements needed for the Physical exam?
undressed patient, clothed in an examining gown
adequate illumination - natural light or bright overhead lighting
an examining provider prepared to see what is there
-
lesions that may accompany the presenting complaint
unrelated but important incidental findings
what type of lighting can be used to detect subtle elevations?
side lighting
what is used to accentuate pigmentary alternations in the skin, like vitiligo?
woods light
an illuminated handheld magnifying device intended to help the clinican to diagnose melanoma clinically
dermatoscope
why should you palpate the skin as well? (2)
- to assess the texture consistency and tenderness of the skin lesion
- to reassure patients that we are not afraid to tough their skin lesions
the most important task in the physical examination is to _____
characterize the morphology of the basic lesion
scale, lichenification, vesciles, bullae, pustules and crusts are all ___ alterations
epidermal
erythema, purpura, and induration reflect changes in the __
dermis
epidermal growths results from ___ of keratinocytes
hyperplasia
__ accumulates hen the rate of stratum corneum production exceeds the rate of shedding
scale
excessive accumulation of keratin
hyperkeratosis
malignant epidermal growths usually feel ____
indurated
term designate thickening of the dermis
indurated
what are examples of hyperpigmented macules that results from increased melanin production
freckles
__ and __ are examples of growths characterized by increased numbers of melanin-producing cells
nevi and melanomas
dermal and subcutaneous growths result from ___ proliferative processes in the dermis or subcutaneous fat, most are fully appreciated by palpation
focal
a ___ is often required for the diagnosis of a dermal nodule
skin biopsy
thickened skin with accentuated skin markings
lichenification
__ is the hallmark of chronic dermatitis
lichenification
scaling eruptions are the result of thickened stratum ___
corneum
fish skin
ichthyosis
white or light tan and flakes off rather easily
scale
dried serum and debris on the skin surface and is usually darker, most often yellow or brown, it is adherent and a weeping base is revealed
crust
__ are usually associated with vesicles, bullae, pustules and malignant growths
crusts
__ occur when fluid accumulates within or beneath the epidermis, occur either intraepidermally or subepidermally
vesicles and bullae
__ blisters are tense and less easily broken
subepidermal blister
__ blisters are flaccid and easily ruptured
intraepidermal blister
hypopigmentary changes are accentuated with _____ examination
woods light
t/f erythema is blanchable
true, the increased blood in the skin is contained within dilated blood vessels
t/f purpura is blanchable
false, blood has extravasated from disrupted blood vessels into the dermis so not blanchable
test for blanchability is ___ - simply applying pressure with a finger or glass slide and observing color changes
diascopy
__ rashes are subdivided into generalized, localized and specialized types
erythematous
a special type of blanchable, transient, erythematous lesion of the skin
wheal / hive
purpuric rashes are subdivided into __ and ___ categories
macular and papular
flat and nonpalpable
macular purpura
elevated and palpable
papular purpura
what type of purpura occur in 2 settings: conditions associated with increased capillary fragility and bleeding disorders
macular purpura
disruption and necrosis of the blood vessel caused by inflammatory reaction are called __
necrotizing vasculitis (papular purpura)
idiopathic disorder of increased collagen deposition
scleroderma
totally devoid of epidermis and some or all of the dermal tissue is missing, may extend down to the bone
ulcer
__ processes can result in ulcerations that do not heal, for this reason, all chronic ulcers should be biopsied
malignant
loss of hair
alopecia
to determine whether alopecia is scarring or non scarring, look for the presence or absence of __
follicular openings
inflammation and scaling in the nail bed result in separation of the nail plate from the bed
onycholysis
what are the 4 types of configurations of a rash
linear
grouped
annular
geographic
a flat skin lesion recognizable because its color is different from that of the surrounding normal skin
macule
a macule with some surface change, either slight scale or fine wrinkling
patch
small elevated skin lesions less than 0.5 cm in diameter
papules
an elevated plateau like lesion greater than 0.5 cm in diameter but without substantial depth
plaque
elevated, marble like lesions more than 0.5 cm in both diameter and depth
nodules
blisters filled with clear fluid, less than 0.5 cm
vesicle
blister filled with clear fluid, great than 0.5 cm
bullae
vesicles filled with cloudy or purulent fluid
pustules
liquid debris that has dried on the surface of the skin
crust
__ results from breakage of vesicles, pustules, or bullae
crust
visibly thickened stratum corneum, dry and usually whitish
scale
visible and palpable thickening of the skin with accentuated skin markings
epidermal thickening - lichenification
dermal thickening resulting in the skin that feels thicker and firmer than normal
induration
induration is in the DERMIS
a thin, linear tear in the epidermis
fissure
wider but is limited in depth, confined to the epidermis
erosion
defect devoid of epidermis as well as part of all of the dermis
ulcer
loss of skin tissue
atrophy
a papule or plaque of dermal edema, central pallor and irregular borders
wheal
superficial blood vessels enlarged sufficiently to be clinically visible
telangiectasia
serpiginous tunnel or streak is caused by a ___ organism
burrowing – scabies
noninflammatory lesions of acne that result from keratin impaction in the outlet of the pilosebaceous canal
acne - comedo
contact dermatitis from poison ivy will demonstrate a ____ configuration
linear
herpes simplex will demonstrate a ___ configuration
grouped
tinea corporis will demonstrate a ___ configuration
annular scaling patch
when morphology and configuration (or distribution) appear to conflict, who wins??
morphology
