The Dermatologic Examination Flashcards
Define Primary Lesion
–first recognizable skin lesion or involved basic skin changes.
Define Secondary lesion
–evolve from primary skin lesions, either because of the natural history of the disorder (e.g., crusts in chicken pox) or because of scratching or infection.
Define Distrubtion of skin lesions
–refers to where on the body the lesions are found (e.g., hands, face, trunk, flexor or extensor surfaces).
What are the three layers of the skin?
- Epidermis
- Dermis
- Subcutaneous
Define Vellus Hair
–short, fine, inconspicuous and usually unpigmented (peach fuzz).
Define Terminal Hair
–coarser, thicker and pigmented. Example: - scalp, eyebrows, pubic region.
What are the three growth phases of hair?
–Catagen phase – transitional phase – 3%
–Telogen phase – resting phase – 10-15%
–Anagen phase – Growing phase – 85-90%
What is nail clubbing?
-rounding of the nail. Soft and spongy.
What are etiologies of nail clubbing?
Congenital
Chronic hypoxia
Heart disease
Lung cancer
Hepatic cirrhosis
What is an etiology of nail pits?
Psoriasis- nail can also thicken.
What are the two kinds of nail lines discussed and what causes them?
Mee’s lines and Beau’s Lines
Emerge from the proximal nail folds, may follow an acute or chronic illness, chemotherapy
What are the 4 skin pigments discussed and what causes each one?
–Brown – Melanin (melanocytes)
–Yellow – Carotene, Jaundice (bilirubin)
–Red - Carboxyhemoglobin–(CO poisoning), Polycythemia
–Bluish-red - De-oxyhemoglobin–(cyanosis)
Where in the cell do melanocytes make melanin?
Melanosomes
What determines a persons skin pigment?
The ammount melanin present
Define Macule
Small flat spot, <1.0 cm
Define Patch:
Patch: Flat spot or lesion, >1.0 cm
Define Papule
Papule: Raised lesion, <1.0 cm
Plaque:
Plaque: Raised lesion, >1.0 cm
Nodule:
Nodule: Firm, hard lesion, deeper than a papule, >0.5 cm
Cyst:
Cyst: Nodule filled with material, liquid or semi-solid, often encapsulated.
Vesicles:
Vesicles: Fluid filled lesions, <1.0 cm, single or in clusters
-Bulla:
-Bulla: Fluid filled lesion, >2.0 cm
-Wheal:
-Wheal: Superficial localized raised area of skin, blanches with pressure
-Pustule:
-Pustule: Open lesions filled with pus.
Scale:
Scale: Flaking of dead exfoliated epidermis.
-Crust:
-Crust: Dried residue of skin exudates such as serum, pus or blood.
Fissure:
Fissure: Linear crack in skin
-Ulcer:
-Ulcer: Deeper loss of epidermis
Lichenification :
thickening of the epidermis and roughing of the skin surface often from rubbing or scratching.
Excoriation
Excoriation – linear erosions caused by scratching.
Koebner phenomena
Koebner phenomena – skin trauma from scratching may cause new lesions
You do a KOH prep to look for?
hyphae or pseudohyphae indicate a fungal infection/yeast infection.
You do a gram stain to look for?
gram + or gram - bacteria.
You do a Tzanick stain to look for?
looking for herpes virus infection with rounded, multinucleated keratinocytes.
You do an Oil mount to look for?
Oil mount: Skin scraping from base of burrow or non-excoriated papule, looking for mites/eggs and scabies infection.