Skin Flashcards
Epidermis
- Barrier from environment
* waterproof
Dermis
Blood vessels, hair follicles sebaceous glands, sweat glands nails, apocrine glands
Structural support, flexibility, sensation
Hypodermic (subq)
Subcutaneous fat and connective tissue
Deepest layer
Conserves heat
Layers of epidermis:
Corneum: superficial, shed dead skin Lucidum: only hands + feet (palmar and plantar Granulosum: keratinization Spinosum: spiny shaped calles (strength Basale: cells germinate (keratinocytes
Keratinocytes
Hyperproliferation -> BCC and SCC
Melanocytes
Hyperproliferation -> melanoma
Papillary dermis
Superficial dermis
Loose network of collagen bundles
Reticular dermis
Deep dermis
Densely packed and thick collagen bundles
Ground substance
Layer of dermis
Eccrine glands
Cover most of body
No odor
Ducts open at skin surface
Apocrine glands
Concentrated in axilla and genitalia
Secretes into sac of hair follicles
Releases thick, odorless fluid -> mixes with skin bacteria -> produces odor
Triggered with stress, hormones, etc.
Vellus hair
Short and fine (forehead)
Terminal hairs
Long and thick (scalp/axillae)
Bulb of hair follicle
Enlargement at base
Melanocytes within matrix contribute to hair pigment
Skin lesion external factors
Topical irritant/allergens, seasonal, travel, temperature, previous treatment, occupation, hobbies, pregnancy
Color concerns
Hyper- vs hypopigmentation
Pallor
Central cyanosis (pulm or cardiac disease)
Peripheral cyanosis (cooler temps or anxiety)
Jaundice
General skin inspection
Moisture
Temperature
Texture (soft and smooth = normal)
Turgor (check hydration status)
Flexor Distribution
Atopic dermatitis (eczema)
Extensor distribution
Psoriasis
Seborrheic distribution
Scalp, face and presternal
Sun-exposed site distribution
Light sensitive disorder
Round/discoid shaped
Coin shaped
No central clearing = eczema
Umbilicated lesions
Ovoid shape
Pityriasis rosea
Annular shape
Round
Active margins with central clearing
Seen in tinea
Dermatomal arrangement
Follow nerve segment
Herpes or varicella zoster
Target shape
Pink macules with purple central papules
Seen in erythema multiforme
Linear arrangement
Phytophotodermatitis
Serpiginous arragement
Cutaneous larva migrans
Morbiliform arrangment
Erythematous maculopapular lesions that become confluent on face and body (measles like)
Primary lesions
Arise from previously normal skin
Secondary lesions
Arise from changes in primary lesions
Usually due to exogenous factors/changes (scratching, infection, rubbing, crusting)
Macule
Primary lesion
Circumscribed flat, nonpalpable (primary lesion)
<1 cm in diameter
Ex: freckles
Patch
Primary lesion
Flat, non-palpable
> 1cm in diameter
Can be well circumscribed or irregular shape
Ex: cafe au lait spot
Papule
Primary lesion
Palpable, firm, raised
< 1cm in diameter
Flesh colored, red, brown
Ex: seborrheic keratosis
Plaque
Primary lesion
Elevated, firm, palpable
> 1cm in diameter
Ex: psoriasis
Nodule
Primary lesion
Elevated, circumscribed
Deeper and firmer than a papule
Often > 1.5cm in diameter
Can be compressible, soft, rubbery or firm
Ex: epidermal inclusion cyst
Tumor
Primary lesion
Large nodule
Deeper in the dermis
> 2cm in diameter
Ex: lipoma
Wheal
Primary lesion
Irregular
Transient
Superficial edema
Ex: hives (urticaria), insect bite
Vesicle
Primary lesion
Usually associated with a virus
Elevated, well circumscribed
<1cm in diameter
Fluid containing, usually clear
Ex: Varicella Zoster and Herpes Zoster
Bulla
Primary lesion
Elevated
Well circumscribed
> 1cm in diameter
Filled with serous fluid
Ex: bullous pemphigoid
Pustule
Primary lesion
Elevated
Superficial
Well circumscribed
Filled with pus
Ex: folliculitis
Furuncle
Primary lesion
Infection of a single hair follicle
Caused by S. Aureus
AKA boil
Carbuncle
Primary lesion
Infection of multiple hair follicles
Caused by S. Aureus
Can form an abscess
Crust
Secondary lesion
Dried residues of serum, pus or blood
Adherent
Ex: Impetigo
Scale
Secondary lesion
Hyperkeratosis
Accumulation of stratum corneum due to increased proliferation and/or delayed desquamation
Ex: psoriasis
Fissure
Secondary lesion
Linear cleft in skin
Often painful
Results from marked drying, skin thickening or loss of elasticity
Ex: hand dermatitis
Erosion
Secondary lesion
Partial or complete loss of epidermis
Moist, oozing and or crusted lesion
Ex: Pemphigus foliaceus
Ulcer
Secondary lesion
Deeper defect than erosion with loss of at least entire epidermis plus superficial dermis
May go deep through dermis
Ex: venous stasis ulcer
Excoriation
Secondary lesion
Exogenous injury to all or part of the epidermis
Usually due to scratching
Ex: neurotic excoriations
Atrophy
Secondary lesion
Epidermal: thinning of epidermis -> wrinkling and shiny appearance
Dermal: loss of dermal collagen and/or elastin -> depression
Ex: striae
Lichenification
Secondary lesion
Thickening of epidermis
Increased visibility of skin markings
Ex: LSC
Petechiae
Vascular lesions
Deep red/purple, round, irregular
<0.5cm
Non-blanchable
Blood outside of a vessel
Purpura
Vascular lesion
Deep red/purple, round, irregular
> 0.5cm
Non-blanchable
Blood outside of a vessel
Ecchymosis
Vascular lesion
Purple lesions of variable size
Fade to green/yellow/brown
Round/oval, irregular borders
Blood outside of vessel due to trauma
Spider angioma
Vascular lesion
Fiery red lesions
Small in size (up to 2cm)
Central body with surrounding erythema
Blanchable
Common with liver disease and pregnancy
Cherry angiomas
Vascular lesion
Bright red
1-6mm in size
Non-blanchable
Genetic component
Telangiectasia
Vascular lesion
Permanently dilated superficial blood vessels
Blanchable
Irregular
Seen in BCC, rosacea
Hemangioma
Benign vascular neoplasm
Most common tumor in infancy
Red, irregular
Secondary to dilation of capillaries
Starts as macular patch can progress to plaque or nodule
Papulosquamous lesions
Papules, plaques and scales
Ex: psoriasis and lichen planus
Nodular lesions (benign)
Epidermal and dermal nodules
Ex: Nevi, cherry angioms, epidermoid cysts
SCC
Malignant nodular lesion
Isolated keratotic, eroded, papule or nodule
Sun exposed areas
BCC
Malignant nodular
Pearly nodule in sun exposed areas
Central erosion
Telangiectasias
Vesiculobullous lesions
Ex: impetigo, herpes, pemphigus
Maculopapular lesions
Ex: viral exanthems, drug eruptions
Nail clubbing
Rounded, bulbous nail base
Feels spongy
Often occurs with CF or lung diseases
Schamroth’s window/sign
Flex fingers -> bring index fingers until distal phalanges touch
Diamond space in between nails = negative sign/window
No space = positive sign/window
Beau’s lines
Transverse depressions secondary to trauma or acute/severe illness
Paronychia
Inflammation of proximal and lateral nail folds
Acute: <6 weeks
Chronic >6weeks
Onychocryptosis
Ingrown toenail
Nails grow into dermis
Can become infected
Terry’s nails
Mostly white with distal band of reddish brown
“Ground glass” appearance
No lunula
Leukonychia
Trauma to nails causing areas of white discoloration
Koilonychia
Spoon shaped, concave nail
Onycholysis
Painless separation of nail plate from nail bed
Seen in psoriasis
Onychomycosis
Fungal infection of nail bed, plate or matrix
Nail pitting
Small, punctate depressions
Caused by nail matrix inflammation, common in psoriasis