The Skin Flashcards
Seconday lesion
evolves from pirmary skin lesion, (i.e crust of chicken pox) or can be because of scratching or infection
distribution
refers to where on the body the lesions are found (e.g., hands, face, trunk, flexor or extensor surfaces).
3 layers of skin
- epidermis
- dermis
- subcutaneous
vellus hair
short, fine, inconspicuous and usually unpigmented (peach fuzz).
terminal hair
Terminal hair – coarser, thicker and pigmented. Example: - scalp, eyebrows, pubic region.
Three phases of hair
Catagen phase – transitional phase – 3%
Telogen phase – resting phase – 10-15%
Anagen phase – Growing phase – 85-90%
clubbing of nails
rounding of the nail, soft and spongy
Etiologies: Congenital ****Chronic hypoxia*** (i.e. ventricular, septal defect, severe COPD) Heart disease Lung cancer Hepatic cirrhosis
_ people are also ashen appearing and cyanotic
Psoriasis
- small pits in the nails, may be due to cirrohsis
Mee’s lines
discolored lines, due to traumatic event such as illness or metabolic event
Beau’s lines
interruption of growth of nail, appears as an indent
- may follow surgery or metabolic illness
what causes color in skin? brown, yellow, red, blue?
brown: melanin
yellow: carotene, bilirubin (jaundice)
red: carboxyhemoglobin (CO poisoning), polycythemia (increased RBC counts)
bluish-red: de-oxyhemoglobin (cyanosis)
melanocytes
cells containing melanin in organelles called melanosomes. The cells migrate outward to the epidermis.
- albinos: melanin is absent
mobility and turgor
not ease with which skin lifts up - mobility
- note speed which which it returns to place (turgor)
important flexor surfaces?
back of knees, back of neck, back of elbows
- atopic dermatitis is seen here
extensory surface
extensors of elbow and knee
- cirrihosis
- syphillis (palms of hands)
macule
small flat spot, less than 1.0 cm
- benign, loss of melanocytes, not much for treatments
i. e Vitiligo
patch
flat spot or lesion greater than 1.0 cm
i.e. cafe-au-lait spots, looks like little stains of coffee (associated with tumerosclerosis)
papule
raised lesion up to 1.0 cm, reddened
i.e. psoriasis
plaque
raised lesion greater than 1.0 cm
i.e. psoriasis
nodule
firm, hard lesion, deeper than a papule, less than 1/2 cm
cyst
nodule filled with material, liquid or semi-solid - often encapsulated
i.e. inclusion cyst on face, caused by blocked sebaceous gland
vesicles
fluid filled lesions, less than 1.0 cm
- single or in clusters
i.e. herpes zoster virus, found in dermatome skin patches
bulla
fluid filled lesion greater than 1.0 cm
i.e. insect bite
wheal
superficial localized area of skin, blanche with pressure
* these are vascular lesions*
i.e. urticaria
pustule
open lesions filled with pus
i.e. acne
scale
flaking of dead exfoliated epidermis
crust
dried residue of skin exudates such as serum, pus or blood
i.e. impetigo (responds to systemic antibiotics)
lichenification
thickening of skin from rubbing or scratching
- often seen in flexing
excoriation
linear erosions caused by scratching
- Koebner phenomena: skin trauma from scratching may cause new lesions - i.e. spreading of poison oak from scratching
fissure
linear crack in skin
i.e. tinea pedis
ulcer
a deeper loss of dermis
patterns/different shapes?
linear cluster geographic (irregular) serpiginous heliotrope = around eyes annular
what is KOH used for?
use for looking for yeast infections (KOH destroys skin and you see the yeast cells)
gram staining
looking for bacteria
- used for pustule
chains of + cocci = staph
bunches of + cocci = strep
Tzanck smear
used to look for herpes - will see multi-nucleated giant cells
Oil mount
used for looking for Scabei mite from skin scraping
- used for looking for parasites
Basal Cell Carcinoma
- 80% of the skin cancers
- Arise from the basal layer of the epidermis
- Grow slowly, rarely metastasize
- “rodent ulcer”
- curable
Pearl white, domed shaped papule with telangiectasias.
Center can ulcerate, “rodent ulcer”.
Squamous cell Carcinoma
- 16% of the skin cancers
- Arise from the upper layer of the epidermis
- Can metastasize if left untreated
- more aggressive, treated with simple excision
- can look crusty and scaley, not pearly
- Commonly found on head, neck or hands.
May develop from a precursor actinic keratoses
malignant melanoma
- 4% of the skin cancers
- Arise from melanocytes
- Can spread rapidly and metastasize, any organ, including the brain and heart
- Can have high mortality rates
- Risk, 1 in 90
- Fair skinned at higher risk, excessive sun exposure
- May require deforming surgery
ABCDE screening for melanoma
Asymmetry
irregular borders: ragged, notched or blurred
color, especially blue or black
Diameter: greater than 6 mm of different from others, especially changing, itching or bleeding
Elevation or enlargment
