Topic 27 - Skin Disease

Question 1

What system is the skin a part of and what are its appendages?

Answer 1

Integumentary system

Hair and nails

Question 2

What are the functions of skin?

Answer 2

1. Flexible, mechanical barrier to prevent entry of infectious agents and controls loss of fluid from the body
2. Temperature control
   Blood vessels - vasodilatation and vasoconstriction changes body temp
   Sweat glands - sweat evaporates and cools us
   Hairs - pilirection holds a layer of air next to the skin raising the body temp
3. Immune functions
4. Protection versus UV light
   Melanocytes secrete melanin which protects us from UV damage
5. Vitamin D metabolism
6. Nerve endings
   Detect external stimuli such as heat, cold, vibration, denture touch, deep pressure and pain
7. Aesthetics
   Can also communicate mood e.g. blushing
8. Absorption
   Drugs applied topically can be absorbed across the skin

Question 3

Describe the anatomy of the skin.

Answer 3

Stratum corneum is the outermost layer of dermis which is 5 layers thick.
Then basement membrane.
Then dermis. Which contains appendages.
Then hypodermis - not part of the skin. Contains subcutaneous adipose tissue

Question 4

What are some skin cells?

Answer 4

Basal keratinocytes - live in stratum basale and are needed for skin maintenance. Replace the skin cells and important in wound healing. Also are the origin of non-melanoma skin cancers.

Melanocytes.
This is where melanin mainly resides and can then go to keratinocytes. Origin of melanoma cancers.

Question 5

What are the types of normal skin lesions you can get?

Answer 5

FRECKLE
Small brown flat mark which occurs on facial skin or skin that’s been exposed.
Can go after sun exposure.
Proves that melanin is in keratinocytes.

MOLES
Also called melanocytic naevi or melanotic macule.
These are proliferations of melanocyte cells.
Can be pink to black.
Their presentation can change over life and can become flatter/disappear in elderly patients. Position determines whether it’s flat or raised, and the colour.
Junctional - formed at junction between dermis and epidermis. Are flat and colourful.
Compound -
Intradermal naevus - contained in dermis only. Are raised with no colour.

Question 6

What is the number of moles a person has dictated by?

Answer 6

Genetics
sun exposure

Can become darkened with sun expo or pregnancy

Question 7

How can you assess the skin type?

Answer 7

Using a FitzPatrick scale

Question 8

Define sun burn

Answer 8

Damage to DNA that causes cancer risk

Is a tan

Question 9

Is sun damage okay the next summer like do you reset?

Answer 9

No, sun damage is cumulative

Question 10

What is photoaging?

Answer 10

Damage due to UV radiation.

Wrinkles, discolouration, rough leathery skin, freckle

Question 11

What’s another word for freckle?

Answer 11

Ephelis

Plural ephilides

Question 12

What is solar lentigo?

Answer 12

Lentigines = plural.

Also called liver spots or age spots.

Large flat brown spots on the face and hands that can occur in middle age due to sun exposure. Can persist for a long time and don’t fade in winter.

Question 13

How does sun cause skin cancer risk?

Answer 13

UVA and UVB radiation - UVB radiation more harmful.

Causes DNA damage which can increase risk of primary skin cancers.

Question 14

What is actinic/solar keratosis and how is it managed?

Answer 14

Sun exposure which causes single or cluster of pink-yellow/black maculae and papules, rough and scaly, on the skin. can be on scalp, face, hands.

Patient is asymptomatic with mild inflamamtin.

Can increase risk of cancer.
So perform biopsy sometimes.

Give sun exposure information and advice.

And medication may be required (given in ebook)

Question 15

What is actinic cheilitis?

Answer 15

Actinic keratosis on lip corners.

Question 16

What type of skin cancers can you get? Broad categories.

Answer 16

Melanoma skin cancer.
Non-melanoma skin cancer: SCC, BCC, others
Secondary metastases

Question 17

WHat are some risk factors for melanoma?

Answer 17

Pale skin
Light eyes
Red or blonde hair
UV exposure

Question 18

Who are high risk patients for melanoma?

Answer 18

Changing moles
Moles
relatives with melanoma
Eldelry

Question 19

What are the types of melanomas?

Answer 19

1. Superficial - grows slowly horizontally then invades deep tissues. Urgent referral needed to be curative before it goes deep
2. Nodular - Dark brown, rapidly grow. Sun exposed areas.
3. Lentigo maligna - develop in a preexisting macule slowly, and when metastases occurs, grows aggressively.
4. Acral lentigines - soles of feet, palms, under nail bed. In dark skinned people, most common melanoma. Unrelated to sun exposure.

Question 20

What is amelanotic melanoma relevance to us?

Answer 20

Many mucosal melanoma are amelanotic.

Biopsy required.

Question 21

How do you manage melanoma?

Answer 21

Primary prevention - sun exposure advice, can give some creams.
Secondary prevention - refer to derm who surveilles moles

ABCDE of pigmentation assessment