Dermatology Flashcards
Three Skin Layers (3)
- Epidermis: Horny layer of dead cells, melanin and keratin are formed
- Dermis: supportive layer, connective tissue, appendages embedded vasculature and peripheral nervous system
- Subcutaneous fatty layer: fat storage
Anatomic Depth of a Lesion: Epidermis (5)
Altered Surface Markings with scales, crust and color changes
- Vitiligo
- Atopic dermatitis
- Café au lait spot
- Impetigo
Anatomic Depth of a Lesion: Epidermis and Dermis (5)
- Altered surface markings plus distinct borders, edema, scales, vesicles, crust, color changes including red
- Psoriasis
- Atopic dermatitis
- Cutaneous lupus erythematosus
- Contact dermatitis
Anatomic Depth of a Lesion: Dermis (5)
- Normal surface markings with color changes and dermal firmness
- Urticaria
- Granuloma annulare
- Hemangioma
- Blue nevus
Anatomic Depth of a Lesion: Subcutaneous Tissue (3)
- Normal surface markings with normal or red skin color and altered skin firmness
- Hematoma
- Erythema Nodosum
Vitiligo (3)
- Associated with autoimmune disease such as thyroid disease destruction of melanocytes with loss of melanocytes
- Can be localized, generalized or segmental
- Can have zones of transition from normal to hypopigmented skin
Ectodermal Dysplasia
Lack the ability to sweat; run high fevers and may get seizures as a result
Mongolian Spots
Excess melanocytes in one area; seen more commonly in darker skinned children because they have more melanocytes
Over time, the melanocytes migrate so the children loose their mongolian spots (usually around age 2 but can stay longer)
Post-inflammatory hyperpigmentation
Scratching leads to increased melanocytes; skin gets darker and many times it thickens (lichenification)
Pityriasis Alba
Essentially dry skin; patches of white or paler skin will come up, mainly occurring in summer and winter
Oculocutaneous Albinism (4)
- MUST protect skin since will develop freckles, actinic keratoses and carcinoma of the skin
- Unable to produce melanin
- Red orange hair
- Nystagmus and photophobia
Addison’s Disease
Causes increased pigmentation due to adrenal insufficiency
Acanthosis Nigricans (3)
- Hyperpigmentation and hyperkeratosis in intertriginous areas and over bony prominences.
* Seen on nape of neck, knuckles of hands - Skin lines are accentuated, and the skin surface of involved areas may have a velvety, leathery, or warty appearance
- Occurs with hyperinsulinism or obesity
Assessment of Nevi (ABCDE)
ABCDE – Asymmetry – Border irregularity – Color variation – Diameter of > 6 mm – Evolution
*Ugly duckling sign: A nevi outside the common
pattern may need biopsy
Six Pronged Approach to a Rash
- What kind of lesion is it?
– Primary or secondary? - Where is located on the body?
- How are the lesions configured?
- How are the lesions spreading?
- What is the original color and what are the secondary color changes?
- What symptoms are associated with the rash?
Exanthem
Rash on the skin; could be chicken pox, coxi virus, etc.
Enanthem
Rash inside a mucous membrane; can get this from varicella or other infections (ex: rash in penis, mucous membranes of mouth, etc)
Macule
flat, distinct, discolored area of skin that is usually less than 1 centimeter wide.
Patch
a macule greater than 1cm wide
Papule, Plaque
Solid raised lesion that has distinct borders and is less than 1 cm in diameter.
- may have a variety of shapes in profile (domed, flat-topped, umbilicated) and may be associated with secondary features such as crusts or scales.
- Two erythematous papules next to each other is the hallmark of spider bites
Plaque: greater than 1cm diameter; bigger and raised
*Associated with psoriasis; when you scratch it, it bleeds (aspitz sign)
Nodule, Tumor
Nodule: A nodule is a raised solid lesion more than 1 cm. and may be in the epidermis, dermis, or subcutaneous tissue.
Tumor: larger than nodule
Wheal, uticaria
wheal: A wheal is an area of edema in the upper epidermis.
uticaria: hives
Vessicle, Bulla
Vessicle: Vesicles are raised lesions less than 1 cm. in diameter that are filled with clear fluid.
Bulla: greater than 1cm
Pustule
Pustules are circumscribed elevated lesions that contain pus. They are most commonly infected (as in folliculitis) but may be sterile (as in pustular psoriasis)
Cyst
A cyst is a closed sac that contains liquid or semisolid material. On palpation a cyst is usually resilient.
Psoriasis
- Red, welldemarcated plaques covered with dry, thick, silvery scales
- tend to be located on the extensor surfaces of the
extremities, the scalp, and the buttocks, or large lesions over the pressure points of the knees and elbows - Ausptiz sign: scratching a psoriasis scale causes bleeding
Guttate
Drop-like lesion
Tumor - Lipoma
Under the skin, generally involving subcutaneous fatty layers
Varicella Zoster
vesiculopustular exanthems; goes in line of dermatome track (dermatomal)
*usually seen across chest or back
Varicella
vesicles, papules, and scabs can occur all in the same stage of the illness
Vesicles in Groups
Herpes until proven otherwise!; the vesicles in herpes crust over and are grouped together in a cluster
*Think of herpes any time you see vesicles
*Herpes leaves scabbing after the vessicles go away
Vesicles
In groups: herpes simplex
In chains: herpes zoster
Secondary Skin Lesions (10)
- Crust
- Scale
- Fissure
- Erosion
- Ulcer
- Excoriation
- Scar
- Atrophic Scar
- Lichenification
- Keloid
Ehler Danlos syndrome
connective tissue disorder marked by cigarette thin; has atrophic scars
Erosion v. Ulcer
Erosion: a loss of epidermis
Ulcer: a loss of epidermis and dermis
Fissure
Break in the skin
Excoriation
if erosions and/or ulcers are produced by scratching