Introduction to General Dermatology

Question 1

What proteins make up the dermis?

Answer 1

Collagen, elastin and fibroblasts with macrophages

Question 2

What is the function of melanocytes?

Answer 2

Makes melanosomes (collections of melanin) and excretes them into keratinocytes

Question 3

What is the function of langerhans cells?

Answer 3

To process antigens and migrate to lymph nodes to induce an immune response

Question 4

What are the three phases of the hair cycle?

Answer 4

Anagen
Catagen
Telogen

Question 5

What percentage of hairs are in each phase of the hair cycle at any given time?

Answer 5

Anagen- 80-90%
Catagen- 1-3%
Telogen- 10%

Question 6

What occurs in each phase of the hair cycle?

Answer 6

Anagen- active growing phase
Catagen- growth stops/follicles shrink
Telogen- resting phase

Question 7

From deep to superficial, what are the layers of the epidermis?

Answer 7

Stratum basale
Stratum spinosum 
Stratum granulosum 
Stratum Lucidum 
Stratum Corneum

Question 8

What are the main functions of the skin?

Answer 8

Thermoregulation 
Skin immune system 
Barrier 
Sensation
Vitamin D synthesis 
Interpersonal communication

Question 9

What is the definition of macule?

Answer 9

A small flat lesion

Question 10

What is the definition of a patch?

Answer 10

A large flat region

Question 11

What is the definition of papule?

Answer 11

A small raised lesion

Question 12

What is the definition of plaque?

Answer 12

A large raised lesion

Question 13

What is the definition of vesicle?

Answer 13

A small fluid filled lesion

Question 14

What is the definition of bulla?

Answer 14

A large fluid filled lesion

Question 15

What is the definition of pustule?

Answer 15

A small pus filled lesion

Question 16

What is the definition of abscess?

Answer 16

Large pus filled lesion

Question 17

What is the definition of an erosion?

Answer 17

Loss of the epidermis

Question 18

What is the definition of an ulcer?

Answer 18

Loss of the epidermis and the dermis

Question 19

What is eruptive xanthoma a sign of?

Answer 19

Hyperlipidaemia

Question 20

What conditions are acanthosis nigricans associated with?

Answer 20

Insulin resistance
Obesity
Malignancy

Question 21

What are the characteristics of acanthosis nigricans?

Answer 21

Flexural distribution of “velvety” looking skin
Hyperkeratosis
Hyperpigmentation
Papules

Question 22

What are the characteristics of thyroid skin disease?

Answer 22

Pretibial myxoedema

Question 23

What investigations can be useful it a bacterial infection is suspected?

Answer 23

Charcoal swab

Microscopy, culture and sensitivities (MC&S)

Question 24

What investigations can be useful it a viral infection is suspected?

Answer 24

Viral swab for PCR

If systemically ill, throat swab

Question 25

What investigations can be useful it a fungal infection is suspected?

Answer 25

Skin scraping Nail clipping Hair sample Fungal cultures