Lecture 1: Introduction into General Dermatology

Question 1

Outline the structure of skin

Answer 1

3 main layers:

Epidemris: 90% keratinocytes and is made up of 5 layers
Dermis
Hypodermis (subcutaneous tissue)

Question 2

Describe the 5 layers of the epidermis

Answer 2

1. Stratum basale:
   - Cells divide by mitosis and becomes cells of the more superficial strata
2. Stratum spinosum:
   - Keratin fibres and lamellar bodies accumulate
3. Stratum granulosum:
   - Keratohyalin and hard protein envelope form
   - Lamellar bodies release lipids
   - Cells die
4. Stratum lucidum:
   - Dead cells lie within dispersed keratohyalin
5. Stratum corneum:
   - Dead cells with a hard envelope protein containing keratin and surrounded by lipids

Process takes 90 days- accelerated in particular pathologies such as psoriasis

Question 3

Outline the nail anatomy

Answer 3

Hyponychium: top of the nail

Nail plate

Nail bed: flesh under the nail

Lanula: white at the base of the nail

Lateral and proximal nail folds

Cuticle

Nail matrix: at the bottom- where the nail grows from

Question 4

State the 3 stages of the hair cycle

Answer 4

Anagen phase:

Active growth

Catagen:
- Ceasing of growth/shrinkage

Telogen: hair shed

Question 5

What are the functions of the skin

Answer 5

1. Thermoregulation
2. Communication
3. Protection
4. Immune function
5. Sensation
6. Vitamin D synthesis

Question 6

Why is skin disease important ( 5 Ds)

Answer 6

1. Disfigurement
2. Discomfort
3. Disability
4. Depression
5. Death

Question 7

External causes of skin disease

Answer 7

Trauma
Photosensitivity
Chemical 
Infection
Cold injury

Question 8

Internal causes of skin diseae

Answer 8

Genetic
Drugs
Autoimmune

Question 9

Define a macule & patch

Answer 9

Macule:

Small flat circumscribed area- non palpable change in skin colour with distinct borders

Patch:
Large flat circumscribed area

Question 10

Define papule and plaque

Answer 10

Papule:

Small raised area

Plaque:

Large raised area

Question 11

Define vesicle and bulla

Answer 11

Vesicle:

Small fluid filled

Bulla:

Large fluid filled

Question 12

Define pustule and abscess

Answer 12

Pustule:

Small pus filled

Abscess:

Large pus filled

Question 13

Define erosion and ulcer

Answer 13

Erosion:

Loss of epidermis

Ulcer:

Loss of epidermis and dermis

Question 14

State the most common skin conditons

Answer 14

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

Question 15

What is eruptive xanthoma

Answer 15

Sign of hyperlipidaemia

Fatty deposits in the skin

Question 16

What is thyroid skin disease

Answer 16

Build up of mucin in the skin

Question 17

Investigations for a suspected bacterial infection

Answer 17

Charcoal swap

Question 18

Investigations for a suspected viral infection

Answer 18

Viral swab of vesicle fluid

Systemic: throat swab

Question 19

Investigations for a suspected fungal infection

Answer 19

Skin scraping
Nail clipping
Hair sample