Introduction to Dermatology

Question 1

What is the largest organ in the body?

Answer 1

Skin

Question 2

What are some skin adnexal structures?

Answer 2

Hair

Nails

Glands

Sensory structures

Question 3

What are important functions of the skin?

Answer 3

• Protection
• Homeostasis
• Transmission of sensation

Question 4

What are the layers of the skin from superficial to deep?

Answer 4

Epidermis

Dermis

(then below but not part of the skin is the hypodermis)

Question 5

What are the layers of the skin from superficial to deep (invidividual layers)?

Answer 5

Stratum corneum

Stratum lucidum

Stratum granulosum

Stratum spinosum

Stratum basale

Question 6

What forms the stratum corneum?

Answer 6

Dead cells with a hard protein envelope

Cells contain keratin and are surrounded by lipids

Question 7

What forms the stratum lucidum?

Answer 7

Dead cells lie within despersed keratohyalin

Question 8

What forms the stratum granulosum?

Answer 8

Keratohyalin and a hard protein envolope

Lamellar bodies release lipids

Cells die

Question 9

What forms the stratum spinosum?

Answer 9

Keratin fibres and lamellar bodies accumulate

Question 10

What forms the stratum basale?

Answer 10

Cells divide by mitosis and some of the newly formed cells become the cells of the more superficial streta

Question 11

What within the skin releases lipids?

Answer 11

Lamellar bodies

Question 12

What is A?

Answer 12

Hyponychium

Question 13

What is B?

Answer 13

Nail plate

Question 14

What is C?

Answer 14

Lateral nailfold

Question 15

What is D?

Answer 15

Nail bed

Question 16

What is E?

Answer 16

Lunula

Question 17

What is F?

Answer 17

Cuficle

Question 18

What is G?

Answer 18

Proximal nailfold

Question 19

What is H?

Answer 19

Nail matrix

Question 20

What are the 3 different stages of the hair cycle?

Answer 20

Anagen

Catagen

Telogen

Question 21

What is the anagen phase of hair cycle?

Answer 21

Active growing phase

Question 22

What is the catagen phase of hair cycle?

Answer 22

2-3 week phase growth stops/follicles shrink

Question 23

What is the telogen phase of hair cycle?

Answer 23

Resting phase for 1-4 months

Question 24

How long does the telogen phase of hair cycle last?

Answer 24

1-4 months

Question 25

How long does the catagen phase of hair growth last?

Answer 25

2-3 weeks

Question 26

During what phase of the hair cycle is most hair in?

Answer 26

Anagen (80-90% hair) Telogen (up to 10% of hair) Categen (1-3% of hair)

Question 27

What are some functions of the skin?

Answer 27

* 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

Question 28

The skin acts as a barrier to protect against what?

Answer 28

Mechanical, chemical, microorgasms and UV light

Question 29

What kinds of sensations does the skin transmit?

Answer 29

Temperature Touch Pain

Question 30

How does the skin perform vitamin D synthesis?

Answer 30

UV light converts 7-dehydrocholesterol to cholecalciferol

Question 31

How much of skin disease is skin cancer/lesions?

Answer 31

50%

Question 32

Why is skin disease important?

Answer 32

* Disfigurement * Discomfort * Disability * Depression * Death

Question 33

What are some causes of skin disease?

Answer 33

* External * Temperature * Cold injury * Frostbite, chilblains * Skin necrosis * Cold urticaria * 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) * Internal * Systemic disease * Genetics * Drugs * Think of OTC drugs * Infection * Autoimmune * Bullous pemphigoid

Question 34

What can cold injuries to the skin cause?

Answer 34

Frostbite, chilblains Skin necrosis Cold urticaria

Question 35

What are chilblains?

Answer 35

Small lesions caused by inflammation of small blood vessels due to exposure to cold air

Question 36

What is cold urticaria?

Answer 36

Disorder where hives (urticaria) or large red welts form on the skin after exposure to a cold stimulus

Question 37

What is a skin lesion solely produced by patients own actions called?

Answer 37

Dermatitis artefacta

Question 38

What is an example of an autoimmune skin disease?

Answer 38

Bullous pemphigoid

Question 39

What is the morphology of a skin lesion?

Answer 39

Appearance of a skin lesion

Question 40

How big is a "small" skin lesion?

Answer 40

Typically means less than 5mm

Question 41

What are some descriptive words for skin lesions?

Answer 41

* 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

Question 42

What is a macule?

Answer 42

Small circumscribed area

Question 43

What is a patch?

Answer 43

Larger circumscribed area

Question 44

What is a papule?

Answer 44

Small raised area

Question 45

What is a plaque?

Answer 45

Larger raised area

Question 46

What is a vesicle?

Answer 46

Small fluid filled lesion

Question 47

What is a bulla?

Answer 47

Large fluid filled lesion

Question 48

What is a pustule?

Answer 48

Small pus filled lesion

Question 49

What is an abscess?

Answer 49

Large pus filled lesion

Question 50

What is an erosion?

Answer 50

Loss of epidermis

Question 51

What is an ulcer?

Answer 51

Loss of epidermis and dermis

Question 52

What is a lesion?

Answer 52

A region in an organ or tissue which has suffered damage through injury or disease

Question 53

What does distribution of a lesion refer to?

Answer 53

How skin lesions are scattered or spread out

Question 54

What are the different kinds of distributions of lesions?

Answer 54

Isolated or multiple

Question 55

What is used to describe skin lesions?

Answer 55

Morphology Distribution

Question 56

What are some examples of common skin conditions?

Answer 56

Question 57

What are some examples of general conditions that can have cutaneous signs?

Answer 57

* Erythema nodosum * Sarcoidosis * Vasculitis * Malignancy * Auto-immune conditions

Question 58

What does cutaneous mean?

Answer 58

Relating to or affecting the skin

Question 59

What is a skin sign of hyperlipidaemia?

Answer 59

Eruptive xanthoma

Question 60

What is acanthosis nigricans?

Answer 60

Brown to black, poorly defined, velvety hyperpigmentation of the skin Hyperkeratosis and hyperpigmentation

Question 61

What is acanthosis nigricans associated with?

Question 62

What investigations should be done if bacterial infection is suspected for a skin condition?

Answer 62

* Charcoal swab * Ask for MC&S * Microscopy * Culture * Sensitivities

Question 63

What investigations should be done if viral infection is suspected for a skin condition?

Answer 63

* Viral swab for PCR * Can swab vesicle/bulla if vesicular eruption * If systemic illness, can take throat swab

Question 64

What investigations should be done if bacterial infection is suspected for a skin condition?

Answer 64

* Skin scraping * Nail clipping * Hair sample * Fungal cultures

Question 65

What is a simple way to take a skin biopsy?

Answer 65

Punch biopsy