Introduction to Dermatology

Question 1

What adnexal structures are part of the skin?

Answer 1

Hair
Nails
Glands
Sensory structures

Question 2

What are the layers of the skin?

Answer 2

Epidermis
Dermis
Subcutaneous tissue

Question 3

What determines skin colour?

Answer 3

Melanin

Question 4

What are the two types of melanin pigmentation?

Answer 4

Eumelanin
Phemelanin

Question 5

In darker skin tones, is there more eumelanin or phemelanin?

Answer 5

Eumelanin

Question 6

What are the three phases of the hair cycle?

Answer 6

Anagen
Catagen
Telogen

Question 7

Anagen?

Answer 7

Active growing phase

80-90% of hair in this stage

Question 8

Catagen?

Answer 8

2-3 week phase growth stops and the follicle shrinks

1-3% of hair

Question 9

Telogen?

Answer 9

Resting phase for 1-4 months
UP to 10% of hair in a normal scalp

Question 10

Functions of the skin?

Answer 10

Thermoregulation- insulation and heat transfer
Skin immune system
Barrier- protection but also keeps in water and electrolytes
Sensation
Interpersonal communication e.g. physical appearance, smell

Question 11

What vitamin synthesis does the skin play a role in?

Answer 11

The synthesis of vitamin D

Question 12

How does the skin have a role in vitamin D synthesis?

Answer 12

UV light converts 7-dehydrocholesterol to cholecalciferol

Question 13

List some external causes of skin disease.

Answer 13

Temperature
UV light
Chemicals- allergen or irritant
Infection
Trauma

Question 14

What are some of the internal causes of internal disease?

Answer 14

Systemic disease
Genetics
Drugs
Infection
Autoimmune conditions

Question 15

What can cause skin photosensitivity?

Answer 15

Medications

->usually only exposed sites affected, often under the chin and behind ears are spared so worth checking is suspecting due to photosensitivty

Question 16

Which types of light can cause photosensitivity?

Answer 16

UVA, UVB or visible light or a combination of these

Question 17

List some skin conditions which can be caused for external causes.

Answer 17

Cold injury e.g. frostbite, chilblains
Skin necrosis
Cold urticaria

Question 18

Which type of photosensitivity does suncream help with?

Answer 18

UVB photosensitivity

Question 19

The following terms can be used to describe skin lesions.
Vesicle?

Answer 19

Small fluid filled lesions

Question 20

The following terms can be used to describe skin lesions.
Bulla?

Answer 20

Large fluid filled lesion

Question 21

The following terms can be used to describe skin lesions.

Pustule?

Answer 21

Small pus filled lesion

Question 22

The following terms can be used to describe skin lesions.

Abscess?

Answer 22

Large pus filled lesion

Question 23

The following terms can be used to describe skin lesions.

Erosion?

Answer 23

Loss of epidermis

Question 24

The following terms can be used to describe skin lesions.

Ulcer?

Answer 24

Loss of epidermis and dermis

Question 25

The following terms can be used to describe skin lesions. Macule?

Answer 25

Non-palpable change in skin colour with distinct borders

Question 26

The following terms can be used to describe skin lesions. Palpule?

Answer 26

Palpable, solid lesion <1cm in diameter

Question 27

The following terms can be used to describe skin lesions. Plaque?

Answer 27

Palpable, solid lesion >1cm in diameter

Question 28

The following terms can be used to describe skin lesions. Nodule?

Answer 28

Palpable lesion >1cm in diameter which is taller than it is wide

Question 29

What is the size difference between a bulla and vesicle?

Answer 29

Vesicle <1cm Bulla >1cm ->most of these definitions mean small <1cm and large >1cm

Question 30

List some of the most common skin conditions.

Answer 30

Acne Psoriasis Rosacea Skin lesions Urticaria Warts Leg ulcers Scalp/nail disorders Eczema Infections

Question 31

What is the treatment of an abscess?

Answer 31

Incision and drainage

Question 32

What is meant by the distribution of dermatosis?

Answer 32

How the lesions are scattered are spread out e.g. are they all close together or spread in different parts of the body

Question 33

What is Acanthosis Nigricans?

Answer 33

Hyperkeratosis and hyperpigmentation and papules Velvet-like appearance Dark brown/grey

Question 34

What is Acanthosis Nigricans associated with?

Answer 34

Insulin resistance Obesity Malignancy

Question 35

List some conditions in which skin signs can point towards the condition.

Answer 35

Erythema Nodosum Sarcoidosis Vasculitis Malignancy Autoimmune conditions

Question 36

If a patient has eruptive xanthoma, many papules (small raised), what might you suspect as an underlying cause?

Answer 36

Hyperlipidaemia

Question 37

What are some investigations used in dermatology if bacterial infection is suspected?

Answer 37

Charcoal swab Microscopy, culture and sensitives of the swab

Question 38

What are some investigations used in dermatology if viral infection is suspected?

Answer 38

Viral swab for PCR If systemic illness, take a throat swab ->can swab vesicle/bulla if vesicular eruption

Question 39

What are some investigations used in dermatology if fungal infection is suspected?

Answer 39

Skin scraping Nail clipping Hair sample Fungal cultures of each

Question 40

What is a simple method used to take a skin biopsy?

Answer 40

Punch biopsy

Question 41

Going back to skin structure, what is the role of the subcutaneous tissue?

Answer 41

Fat energy store Insulation Fibrous bands which anchor skin to fascia

Question 42

What is the predominant cell type in the epidermis?

Answer 42

Keratinocytes

Question 43

What are the three types of cell in the dermis?

Answer 43

Keratinocytes Melanosomes Langerhans cells

Question 44

What do Langerhan cells do?

Answer 44

Process antigens and migrate to lymph noses to induce an immune response

Question 45

What do melanocytes make?

Answer 45

Melanosomes (collections of melanin)