Dermatology lecture

Question 1

What are the 3 layers of the skin?

Answer 1

Epidermis
Dermis
Hypodermis*

Question 2

What is the function of the skin?

Answer 2

Protection
Temperature Regulation
Fluid Regulation
Sensation
Some metabolic & immune function

Question 3

What types of cells does the epidermis have?

Answer 3

Consists of ‘keratinized stratified squamous epithelial cells’
Contains keratinocytes, melanocytes, Merkel cells and Langerhans’ cells

Question 4

Where is the Basal Membrane located?

Answer 4

between epidermis and dermis

Question 5

What is Dermatitis ?

Answer 5

Inflammatory skin lesion

Question 6

What are the 3 types of dermatitis?

Answer 6

Infective
Bacteria, viruses, fungi etc.

Non-specific
Eczematous dermatitis

Characteristic
e.g. Psoriatic, lichenoid

Question 7

Infective dermatitis can be:

Answer 7

• Bacterial
  Impetigo, folliculitis
• Viral
  Herpes, HPV
• Fungal
  Tinea
• Parasitic
  Scabies

Question 8

What is Non-specific Dermatitis commonly called?

Answer 8

eczema

Question 9

What causes Eczema?

Answer 9

Atopic dermatitis (from childhood)

Question 10

Describe the features of Acute Dermatitis

Answer 10

Red (erythema) and itchy (pruritus) due to inflammatory reaction and inflammatory mediators
Spongiosis (fluid accumulation between epidermal cells) leads to vesicle formation
Patients often scratch the vesicles leading to secondary trauma and infection leading to chronic eczema

Question 11

Describe features of Chronic Dermatitis

Answer 11

Skin is thickened, cracked and scaly due to hyper keratinisation.
There is an increase in cells in the stratum spinosum (acanthosis) and the dermis shows increased fibrosis

Question 12

What causes Prurigo Nodularis ?

Answer 12

Continued picking of chronic dermatitis leads to keratinised nodules and further thickening of the dermis

Question 13

Describe features of Lichen Planus

Answer 13

by shiny, flat-topped, firm papules.
Purple in colour, often crossed by fine white lines
Normally on the front of the wrists, lower back, and ankles or on mucous membranes

Question 14

What does Psoriasis look like?

Answer 14

Raised red plaques covered by white scale, often symmetrical

Question 15

What is Impetigo (Bacterial)

Answer 15

Large bullae (clear fluid) or pustules form
Pustules can rupture leaving honey coloured, crusted exudate

Question 16

Who normally catches the impetigo bacterial infection?

Answer 16

Highly contagious, seen mostly in children

Question 17

Bacterial Folliculitis…

Answer 17

Infection of hair follicles by bacteria
Produces tiny pustules
Can lead to destruction of hair follicle and formation of boil in severe cases

Question 18

Erysipelas is….

Answer 18

Caused by Streptococcal infection
Acute inflammation of deep dermis and upper subcutaneous tissue
Most common on lower limbs or face
Shows swelling and erythema with well-defined border

Question 19

What type of tissue is involved in cellulitis?

Answer 19

Deep subcutaneous tissue and occasionally underlying fascia

Question 20

What can cellulitis lead to?

Answer 20

Necrosis of deep tissues of the skin

Question 21

What does Herpes Virus produce on the epidermis?

Answer 21

Blistering lesions

Question 22

What are the three types of Herpes?

Answer 22

Herpes simplex I (non-genital)
Herpes simplex II (genital herpes)
Herpes zoster-varicella (chicken pox/shingles)

Question 23

In shingles what part of the skin is involved?

Answer 23

Affects skin of corresponding dermatome

Question 24

What does a patient with shingles complain of?

Answer 24

Burning pain, tingling, extreme skin sensitivity and pruritus on corresponding dermatome

Question 25

What is shingles?

Answer 25

A Herpes zoster-varicella virus | Believed to be due to dormant virus in sensory dorsal root ganglia from childhood chickenpox

Question 26

What are the three major types of fungi (dermatophytes)

Answer 26

Trichophyton Microsporum Epidermophyton

Question 27

What is fungal skin diseases known as?

Answer 27

‘ringworm’ or ‘tinea’ – name depends on site infected

Question 28

Athletes foot is an example of what type of skin disease?

Answer 28

fungal

Question 29

Where do Basal Cell Carcinomas develop from?

Answer 29

keratinocytes in the basal layer

Question 30

Describe characteristics of BCC

Answer 30

Linked to increased UV exposure Locally invasive – rarely metastasize Lesions can ulcerate and erode deep into tissue – ‘Rodent Ulcer’

Question 31

What are the three main type of BCC?

Answer 31

Nodular Morphoeic Superficial

Question 32

Nodular Basal Cell Carcinoma is:

Answer 32

Most common type of BCC Occurs frequently in those over 50 years Common areas are forehead and face Presents as a firm, raised nodule May show central ulceration with raised pearly edges Composed of small dark cells resembling the basal layer of epidermis Recurrent ulceration is common Can lead to sunken, ulcerated centre with raised border

Question 33

Morphoeic Basal Cell Carcinoma is:

Answer 33

Less Common Is flat thickened yellowish or whitish plaques Sunken or firm, with focal areas of ulceration. Edges are indistinct and tumour may extend to the dermis and beyond the visible, palpable borders

Question 34

What does Morphoeic Basal Cell Carcinoma look like on a patient?

Answer 34

pale scar

Question 35

Superficial Basal Cell Carcinoma looks like

Answer 35

flat, red plaque with irregular edges Slightly dry or scaly and are often eroded and crusted common on the face

Question 36

Why is SBCC confused with dermatitis, psoriasis or tinea?

Answer 36

Grow rather broadly, and generally do not penetrate very deeply into the underlying dermis

Question 37

What is Squamous Cell Carcinoma?

Answer 37

Tumour of the outer epidermis

Question 38

What is Intraepidermal SCC?

Answer 38

‘Bowen’s Disease’ Slowly enlarging erythematous plaque Usually slight scaling and some crusting

Question 39

Describe Invasive SCC

Answer 39

Hardened nodule Thick keratotic scale or hyperkeratosis Can be eroded or ulcerated Can express horny material from lesion

Question 40

What is the two stages of growth in melanoma?

Answer 40

- Radial growth Remains in epidermis, no metastatic potential - Vertical growth Invades dermis, can metastasize through lymphatic or vascular invasion

Question 41

What are some warning signs of melanoma?

Answer 41

Asymmetry Moles that, if divided in half, are not the same on both sides Border Moles with edges that are jagged or blurred Colour Moles that change colour or are multicoloured Diameter Moles that are greater than 6mm in diameter Evolution Moles that have changed size, shape, colour or elevation (rise above skin)

Question 42

What are some risk factors of melanoma?

Answer 42

Phenotype Fair skin, blue eyes, red hair Genetic risk factors Personal or family history of melanoma or skin cancer Presence of naevi Especially presence of atypical naevi, many naevi and/or large congenital naevi UV exposure History of severe sunburn or intense intermittent sun exposure Immunosuppression Usually from other disease or medication

Question 43

What is Port-Wine stain?

Answer 43

A flat, purplish-red or pink area, generally on face or neck Due to slow-growing malformation of capillaries Rarely regresses, but may continue to grow throughout life