Introduction to Dermatology Flashcards
What is the largest organ in the body?
Skin
What are some skin adnexal structures?
Hair
Nails
Glands
Sensory structures
What are important functions of the skin?
- Protection
- Homeostasis
- Transmission of sensation
What are the layers of the skin from superficial to deep?
Epidermis
Dermis
(then below but not part of the skin is the hypodermis)
What are the 5 layers of the epidermis ?
1- Stratum corneum-
2- Stratum lucidum
3- Stratum granulosum
4- Stratum spinosum
5- Stratum basale
What are the 3 different stages of the hair cycle?
1- Anagen
2- Catagen
3- Telogen
What is the anagen phase of hair cycle?
Active growing phase
What is the catagen phase of hair cycle?
lasts for 2-3 week,
is the dying phase where hair growth stops
and
follicles shrink
What is the telogen phase of hair cycle?
Is resting phase and lasts for 1-4 months
this is the shedding phase
How long does the telogen phase of hair cycle last?
1-4 months
How long does the catagen phase of hair growth last?
2-3 weeks
During what phase of the hair cycle is most hair grow?
Anagen (80-90% hair) the fastest phase
Telogen (up to 10% of hair)
Categen (1-3% of hair) the slowest phase
What are the six functions of the skin?
“important to know this, is a common exam question”
- Thermoregulation
- Insulation, heat transfer
- Skin immune system
- Innate and adaptive functions
- Barrier
- Protects against mechanical, chemical, microorganisms, UV light
- Keep in water and electrolytes, macromolecules
- Sensation
- Temperature, touch and pain
- Vitamin D synthesis
- UV light converts 7-dehydrocholesterol to cholecalciferol
- Interpersonal communication
- Physical appearance, smell, self-identity
How much of skin disease is skin cancer/lesions?
50%
Why is skin disease important?
- Disfigurement
- Discomfort
- Disability
- Depression
- Death
What are some causes of skin disease?
- External
- Temperature
- Cold injury
- Frostbite, chilblains
- Skin necrosis
- Cold urticaria
- Cold injury
- UV
- Called photosensitivity
- Commonly caused by medications
- Exposed sites affected
- Can be sensitive to UVA, UVB, visible light or a combination
- Chemical
- Infection (allergen or irritant)
- Trauma
- Dermatitis artefacta (skin lesions solely produced by patients own actions)
- Temperature
- Internal
- Systemic disease
- Genetics
- Drugs
- Think of OTC drugs
- Infection
- Autoimmune
- Bullous pemphigoid
What are chilblains?
Small lesions caused by inflammation of small blood vessels due to exposure to cold air
What is cold urticaria?
is a skin reaction to cold that appears within minutes after cold exposure
What is a skin lesion solely produced by patients own actions called?
Dermatitis artefacta
What is an example of an autoimmune skin disease?
Bullous pemphigoid
What is the morphology of a skin lesion?
Appearance of a skin lesion
How big is a “small” skin lesion?
Typically means less than 5mm
What are some descriptive words for skin lesions?
- Macule
- Small circumscribed area
- Patch
- Larger circumscribed area
- Papule
- Small raised area
- Plaque
- Larger raised area
- Vesicle
- Small fluid filled
- Bulla
- Large fluid filled
- Pustule
- Small pus filled
- Abscess
- Large pus filled
- Erosion
- Loss of epidermis
- Ulcer
- Loss of epidermis and dermis
What is a macule?
1- Small flat circumscribed area
2- Non-palpable, change in skin color, with distinct borders
