Introduction To Clinial Dermatology

Question 1

Information that should be routinely obtained from a dermatological history

Answer 1

• nature, site and duration of problem
• how it has changed over time
• symptoms associated with it
• aggravating and relieving factors
• previous and current treatments
• recent contact, stressors, illness or travel
• history of sunburn and use of tanning beds

Also ask about occupation, hobbies or any animal contact

Question 2

How are lesions described

Answer 2

SCAM

S size and shape
Colour
Associated secondary changes
Morphology and margin (borders)

And if lesion is pigmented use ABCDE
Asymmetry
Irregular BORDER
Two or more COLOURS within the lesion
Diameter >6mm
Evolution

Question 3

What is a lesion

Answer 3

An altered area on the skin

Question 4

Definition of naevus

Answer 4

A localised malformation of tissue structures. A benign growth on skin formed by a cluster of melanocytes.( mole = naevus)

Question 5

Definition of pruritus

Answer 5

Itching

Question 6

Definition of erythema

Answer 6

Redness which blanches on pressure
(Due to inflammation and vasodilation

Question 7

Examples of vascular lesions

Answer 7

Petechiae = small <3mm macules that don’t blanch

Purpura = red/purple due to bleeding into skin (don’t blanch on pressure)

Ecchymosis = larger bruise like patches

Question 8

Characteristics of acne and clinical features

Answer 8

Chronic inflammatory disease of pilosebaceous unit
Prevalence 650 million in world

Normally as a result of seborrhoea (excessive oiliness of skin) bacteria attracted to it and inflammation occurs
Non-inflammatory lesions such as open and close comedones
Inflammatory lesions = papules and pustules
Scarring

Question 9

Open vs closed comedone

Answer 9

Open comedone/ blackhead = enlarged hair follicle filled with melanin

Closed comedone/ whitehead = small raised non-inflamed spot

Question 10

What is a papule

Answer 10

Superficial red inflamed spot without pus
- is palpable and is distinguished from macule which is flat and not raised

Question 11

What is a pustule

Answer 11

Raised red lesions that may be white or yellow and contains pus
Filled with neutrophils

Question 12

Definition of a nodule

Answer 12

Solid lesions that are typically larger and arise deeper within the dermis or subcutis
Tender and painful

Question 13

Definition of a cyst

Answer 13

Papule or nodule that contains fluid so is fluctuant

Question 14

Types of scars

Answer 14

Atrophic (sunken depressions due to not enough collagen)
Hypertrophic (opposite, raised due to excess collagen)

Question 15

Characteristics and clinical features of atopic eczema

Answer 15

Chronic inflammatory condition developing in childhood
Genetic component = increased with asthma + hay fever
Also can be environmentally triggered eg diet + stress

Clinical features = itchy erythematous dry scaly patches on face, extensor aspects of limbs in infants and flexor aspects in children + adults

Question 16

Pompholyx eczema

Answer 16

Affects the hands with small fluid filled blisters (vesicles)

Eg nickel allergy

Question 17

What is a bulla

Answer 17

Essentially a vesicle (fluid filled blister) that is larger than 0.5cm in diameter

Question 18

Characteristics of psoriasis and clinical features

Answer 18

Chronic inflammatory skin disease due to hyper proliferation of keratinocytes and inflammatory cells infiltrating the skin

Caused by complex interaction between genetic, immunological and environmental factors
Precipitating factors include trauma, infection, drugs (beta blockers), stress and alcohol

Question 19

What is erythroderma

Answer 19

Complication of psoriasis
In erythroderma there is hypothermia and high output heart failure and capillary leak syndrome and fluid loss

Question 20

What is the Koebner effect and what conditions cause it

Answer 20

A linear eruption arising at the site of trauma phenomenon

Eg psoriasis, plane warts, vitiligo and lichen planus

Question 21

What is an abscess

Answer 21

Localised accumulation of pus in the dermis or subcutaneous tissues

Question 22

What is the erythrasma

Answer 22

Common condition that affects the skin folds
Caused by gram positive non-spore forming aerobic bacteria

= pink or brown patches with fine scaling and superficial fissures

Question 23

Most common skin cancer: basal cell skin cancer

Answer 23

Is a malignant cancer of the epidermal keratinocytes that rarely metastasises
Slow growing

Risk factors include UV exposure, history of severe sun burn, fair skin, increasing age, male sex, immunosuppression, previous history of skin cancer and genetic predisposition

Question 24

Squamous cell carcinoma characteristics

Answer 24

Caused by dna damage from exposure to ultraviolet radiation or other damaging agents that trigger abnormal changes in squamous cells

Can metastasise
Normally in sun exposed areas of body

Question 25

Malignant melanomas

Answer 25

Invasive malignant tumour of the epidermal melanocytes which has the potential to metastasise

Causes = fair, excessive UV exposure, history of moles or atypical moles and family history or previous history of melanomas

May itch and bleed

Has worst prognosis

Question 26

How is breslows depth scale used to measure tumours

Answer 26

Stage 1 = <0.75mm
Stage 2 = 0.76 to 1.50mm
Stage 3 = 1.51 to 2.25mm
Stage 4 = 2.26 to 3.00mm
Stage 5 = >3.00mm