General Dermatology

Question 1

What are the different layers that make up skin?

Answer 1

Epidermis - avascular outer layer containing 3 cells types tho mainly keratinocytes.

Dermis - Collagen and Elastin matrix with mucopolysaccharide gel. Work horse of skin. Also contains fibroblasts, dermal dendrites cells and, macrophages.

Hypodermis - subcutaneous fat - insulation and energy store with fibrous bands that anchor skin to fascia.

Question 2

What are melanocytes?

Answer 2

Makes melanosomes (pockets of melanin). Excretes this and phagocytosis them into keratinocytes where they sit above the nucleus.

Question 3

What are langerhans cells within the skin?

Answer 3

Processes antigens and migrate to lymph nodes to induce an immune response.

Question 4

What are the functions of the skin?

Answer 4

Thermoregulation

Skin immune system

Barrier - protection against mechanical, chemicals, microorganism’s, UV. Keeps water, electrolytes and macromolecules.

Sensation

Vitamin D synthesis

Interpersonal Communication - identity etc.

Question 5

What are some external causes of skin disease?

Answer 5

Temperature
UV
Chemicals
Infection 
Trauma

Question 6

What is the difference between a chemical being an allergen and being an irritant?

Answer 6

Allergen does not produce the same reaction in each individual whereas an irritant does.

Question 7

What are some internal causes of skin disease?

Answer 7

Systemic disease
Genetics
Drugs
Infection

Question 8

What is the most common cause of photosensitivity?

Answer 8

Medications - mainly NSAIDs and Antihypertensives.

Question 9

What is a Macule?

Answer 9

Small flat area of skin that has a change in colour but not texture.

Question 10

What is a Patch

Answer 10

Large flat area of skin that has a change in colour but not texture.

Question 11

What is a Papule?

Answer 11

Small raised are of skin.

Question 12

What is a Plaque?

Answer 12

Large raised area of skin.

Question 13

What is a Vesicle?

Answer 13

Small fluid filled blister.

Question 14

What is a Bulla?

Answer 14

Large fluid filled blister.

Question 15

What is a Pustule?

Answer 15

Small pus filled lesion.

Question 16

What is an Abscess?

Answer 16

Large pus filled lesion.

Question 17

What is an Erosion?

Answer 17

Loss of epidermis

Question 18

What is an Ulcer?

Answer 18

Loss of epidermis and dermis.

Question 19

What is a petechiae?

Answer 19

Tiny leaky bloody vessels that appear as red/purple spots on skin.

Question 20

What is Purpura?

Answer 20

Leaky blood vessels that appear as larger red/purple spots on skin.

Question 21

What are some of the most common skin conditions?

Answer 21

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

Question 22

What investigation is used if a bacterial infection is suspected?

Answer 22

Charcoal swab and ask for Microscopy, Culture, Sensitivities.

Question 23

What investigation is used if a viral infection is suspected?

Answer 23

Viral swab for PCR.

Can swab a vesicle or bulla by bursting with a sterile needle and swabbing the fluid.

Question 24

What investigation is used if a fungal infection is suspected?

Answer 24

Skin scraping
Nail scraping
Hair sample
Fungal cultures.