Dermatology

Question 1

What is urticaria?

Answer 1

Local increase in permeability of capillaries and small venules
Histamine release causes itchy wheals

Question 2

What is angioedema?

Answer 2

Deeper swelling involving the dermis and subcutaneous tissues
Swelling of tongue and lips

Question 3

What is anaphylaxis?

Answer 3

Bronchospasm, facial and laryngeal oedema and hypotension

Question 4

What is erythema nodosum?

Answer 4

Hypersensitivity reaction causing discrete tender nodules that may become confluent usually on shins
Occur with Group A beta haemolytic strep
TB, pregnancy, sarcoidosis, IBD, chlamydia

Question 5

What is erythema multiforme?

Answer 5

Acute self-limiting condition

Mucosa not involved or limited to one surface

Question 6

What are the features of Stevens-Johnson syndrome?

Answer 6

Mucotaneous necrosis with 2 or more mucosal surfaces involved
Skin involved may be extensive or limited

Question 7

What are the features of toxic epidermal necrosis?

Answer 7

Usually drug induced
Extensive skin and mucosal necrosis and system toxicity
Full thickness epidermal necrosis
Leads to sepsis, electrolyte imbalance and multi system organ failure

Question 8

What are the features of erythroderma?

Answer 8

Exfoliative dermatitis involving over 90% of skin surface
Skin is inflamed, oedematous and scaly
Systemically unwell - lymphadenopathy and malaise

Question 9

What are some causes of erythroderma?

Answer 9

Eczema, psoriasis
Lymphoma
Sulfonyureas, penicillin, allopurinol

Question 10

What are the features of eczema herpeticum?

Answer 10

Widespread eruption of crusted papules, blisters and erosions due to herpes simplex
Fever and malaise

Question 11

What are some complications of eczema herpeticum?

Answer 11

Herpes hepatitis, encephalitis, DIC

Question 12

What is erysipelas?

Answer 12

Acute superficial form of cellulitis - well-defined red border

Question 13

What are the commonest organisms in cellulitis?

Answer 13

Streptococcus pyogenes

Staphylococcus aureus

Question 14

What are the features of staphylococcal scalded skin?

Answer 14

Production of circulating epidermolytic toxin
Develops in a few hours - days
Scald appearance –> large flaccid bulla –> perineal crusting
Very painful

Question 15

What is pityriasis?

Answer 15

Scaly pale brown patches on upper trunk that fail to tan

Question 16

What are some clinical features of basal cell carcinomas?

Answer 16

Usually nodular
Small skin coloured papule 
Surface telangiectasia 
Rolled edge
Ulcerated centre

Question 17

What are some treatments for basal cell carcinomas?

Answer 17

Surgical excision
Radiotherapy
Imiquimod cream

Question 18

What are some clinical features of squamous cell carcinomas (skin)?

Answer 18

Keratoic ill-defined nodules

Locally invasive, can metastasise

Question 19

What are some features that suggest malignant melanoma?

Answer 19

Asymmetrical 
Border irregularity
Colour irregularity 
Diameter >6mm
Evolution - change in size/shape
Symptoms - bleeding/itching

Question 20

What are some treatments for mild acne?

Answer 20

Benzoyl peroxide
Topical antibiotics
Topical retinoids

Question 21

What are some treatments for moderate acne?

Answer 21

Oral antibiotics

Anti-androgens

Question 22

What are some complications of acne?

Answer 22

Hyperpigmentation
Scarring
Deformity

Question 23

What are some clinical features of acne?

Answer 23

Inflammatory disease of pilosebaceous follicles

Non-inflammatory lesions, open and closed comedones

Question 24

What are some different types of psoriasis?

Answer 24

Chronic plaque - most common
Guttae - raindrop lesions
Seborrhoeic - naso-labial and retro-auricular
Pustular - palmar-plantar

Question 25

What are some different patterns of psoriatic arthropathy?

Answer 25

Symmetrical poly arthritis Spondylosis Arthritis mutilans Dactylitis

Question 26

What are some clinical features of bullous pemphigoid?

Answer 26

Tense fluid filled blisters on an erythematous base - trunk and limbs Usually affects the elderly Autoantibodies against antigens between dermis and epidermis

Question 27

What are some clinical features of pemphigus impetigo?

Answer 27

Flaccid easily ruptured blisters forming erosions and crusts - affects mucosal areas Often middle-aged

Question 28

What are some features of venous ulcers?

Answer 28

Painful Malleolar area Large, shallow, irregular Warm skin, pulses present, normal ABPI

Question 29

What are some features of arterial ulcers?

Answer 29

Painful, especially at night Pressure areas Small, defined, deep, necrotic base Cold skin, absent pulse, ABPI<0.8

Question 30

What are some features of neuropathic ulcers?

Answer 30

Painless, abnormal sensation Pressure areas Over calluses Warm skin, pulses present, peripheral neuropathy

Question 31

What are some features of lichen planus?

Answer 31

Itchy flat topped papules symmetrical distribution Lacey white streaks Forearms, wrists, legs

Question 32

What are some differentials for purpura?

Answer 32

Meningococcal septicaemia DIC Vasculitis Senile purpura

Question 33

What are some clinical features of DIC?

Answer 33

Trauma, sepsis, cancer, CLF | Spontaneous bleeding - ENT, GI, respiratory

Question 34

What are some clinical features of vasculitis purpura?

Answer 34

Painful lesions | Legs, buttocks, flanks

Question 35

What are some clinical features of senile purpura?

Answer 35

Elderly, sun damage On extensors Systemically well

Question 36

What are some side effects of retinoids?

Answer 36

Dry skin, lips and eyes Abnormal LFTs and lipids Teratogenic