Intro to General Dermatology

Question 1

Give the basic arrangement of skin structure

Answer 1

Sub cutis
Dermis
Epidermis

Question 2

What is the function of melanocytes?

Answer 2

Makes melanosomes which are excreted and phagocytose into keranocytes where they sit above the nucleus

Question 3

What is the function of Langerhans cells?

Answer 3

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

Question 4

What are the 5 layers of the epidermis? (inner to outer)

Answer 4

1. Stratum basale
2. Statum spinosum
3. Stratum granulosum
4. Stratum lucidum
5. Stratum corneum

Question 5

What does the sub cutis-hypodermis consist of?

Answer 5

Fat

Question 6

What does the dermis consist of?

Answer 6

Collagen and elastin matrix with mucopolysaccharide gel

Question 7

What cells are found in the dermis?

Answer 7

Fibroblasts
Dermal dendritic cells
Macrophages

Question 8

How does the epidermis receive its nutrients?

Answer 8

By diffusion NOT blood vessels

Question 9

Name some components of nail anatomy

Answer 9

Hyponychium 
Nail plate
Lateral nailfold
Nail bed
Lunula 
Cuticle 
Proximal nailfold
Proximal nailfold
Nail matrix

Question 10

What are the 3 stages of the hair cycle?

Answer 10

ANAGEN
CATAGEN
TELOGEN

Question 11

Describe anagen

Answer 11

Active growing phase; 80-90% of hair

Question 12

Describe catagen

Answer 12

2-3 week phase precedes telogen; growth stops/follicle shrinks; 1-3% of hairs

Question 13

Describe telogen

Answer 13

Resting phase for 1-4 months; up to 10% of hairs in a normal scalp

Question 14

What is the condition which involves temporary hair loss following shock, stress or a traumatic event?

Answer 14

Telogen effluvium

Question 15

Give the 6 important functions of the skin (important exam question)

Answer 15

• Thermoregulation
• Skin immune system
• Barrier
• Sensation
• Vit D synthesis
• Interpersonal communication

Question 16

What does the barrier function of the skin protect against?

Answer 16

Mechanical, chemical, microorganisms, UV light

Question 17

What does the barrier function of the skin keep in?

Answer 17

Water + electrolytes, macromolecules

Question 18

What aspects of interpersonal communication does the skin aid in?

Answer 18

Physical appearance
Smell
Self-identity

Question 19

How does the skin aid in vit D synthesis?

Answer 19

UV light converts 7-dehydrocholesterol to cholecalciferol

Question 20

Give the external causes of skin disease

Answer 20

Temp
UV
Chemical (allergen or irritant)
Infection 
Trauma

Question 21

Give the internal causes of skin disease

Answer 21

Systemic disease
Genetics
Drugs
Infection

Question 22

(sidenote lol) Difference between allergen and irritant?

Answer 22

Irritant - reaction no matter who comes into contact with it

Allergen - not the same reaction in everyone

Question 23

What is photosensitivity?

Answer 23

Immune reaction triggered by sunlight (UVA, UVB, visible light or combo) (sparing under chin is indicative)

Question 24

Photosensitivity is commonly cause by what?

Answer 24

Medications (antihypertensives, NSAIDs etc)

Question 25

What are 4 conditions associated with cold injury?

Answer 25

Frostbite Chilblains Skin necrosis Cold urticaria

Question 26

What is dermatitis artefacta caused by? What is a common presentation of it?

Answer 26

Trauma - psychological reasons Commonly on non-dominant hand Patient says 'I just woke up one day and it looked like that'

Question 27

Most common trauma is scratching - can lead to...

Answer 27

ulceration

Question 28

What genetic condition results from 2 copies of the filaggrin gene mutation? (Deficiency)

Answer 28

Icthyosis vulgaris

Question 29

What is another genetic derm condition where tumours grow along the nervous system?

Answer 29

Neurofibromatosis

Question 30

Name an autoimmune derm condition

Answer 30

Bullous pemphigoid

Question 31

Small circumscribed area =

Answer 31

MACULE

Question 32

Larger circumscribed area =

Answer 32

PATCH

Question 33

Small raised area =

Answer 33

PAPULE

Question 34

Larger raised area =

Answer 34

PLAQUE

Question 35

Small fluid filled =

Answer 35

VESICLE

Question 36

Large fluid filled =

Answer 36

BULLA

Question 37

Small pus filled =

Answer 37

PUSTULE

Question 38

Large pus filled =

Answer 38

ABSCESS

Question 39

Loss of epidermis =

Answer 39

EROSION

Question 40

Loss of epidermis and dermis =

Answer 40

ULCER (associated with scarring, contracture, granulation)

Question 41

What does small usually mean?

Answer 41

Less than 5mm

Question 42

Try n name the most common skin conditions

Answer 42

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

Question 43

What is the cause of eruptive xanthoma which should be treated in order to clear derm pathology?

Answer 43

Hyperlipidaemia

Question 44

What is acanthosis nigricans associated with?

Answer 44

Insulin resistance Obesity Malignancy

Question 45

What areas are acanthosis nigricans found in?

Answer 45

Flexural areas

Question 46

What is pretibial myxoedema associated with?

Answer 46

Thyroid disorders - 5% of Graves | Nodules full of mucinous material, also in eyes

Question 47

What derm investigations are done if bacterial infection suspected?

Answer 47

- Charcoal swab | - MC+S (Microscopy, Culture, Sensitivities)

Question 48

What are derm investigations for if viral infection suspected?

Answer 48

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

Question 49

What derm investigations are done if fungal infection suspected?

Answer 49

Skin scraping Nail clipping Hair sample Fungal cultures

Question 50

Simple way to take skin biopsy?

Answer 50

Punch biopsy (4/5ml of anaesthetic then one stitch after)

Question 51

Primary investigation for cellulitis?

Answer 51

Blood culture