Dermatology

Question 1

What is Sweet’s syndrome?

Answer 1

Also known as acute febrile neutrophilic dermatosis has a strong association with acute myeloid leukaemia

Question 2

Name some skin conditions associated with diabetes mellitus

Answer 2

Necrobiosis lipoidica
Shiny, painless areas of yellow/red/brown skin typically on the shin
Often associated with surrounding telangiectasia

Infection
Candidiasis
Staphylococcal

Neuropathic ulcers

Vitiligo

Lipoatrophy

Granuloma annulare
Papular lesions that are often slightly hyperpigmented and depressed centrally

Question 3

What are the genetic associations of psoriasis?

Answer 3

Genetic: associated HLA-B13, -B17, and -Cw6. Strong concordance (70%) in identical twins

Question 4

Describe the immunological pathophysiology is Psoriasis

Answer 4

Abnormal T cell activity stimulates keratinocyte proliferation. There is increasing evidence this may be mediated by a novel group of T helper cells producing IL-17, designated Th17. These cells seem to be a third T-effector cell subset in addition to Th1 and Th2

Question 5

Name some subtypes of psoriasis

Answer 5

Plaque psoriasis: the most common sub-type resulting in the typical well-demarcated red, scaly patches affecting the extensor surfaces, sacrum and scalp
Flexural psoriasis: in contrast to plaque psoriasis the skin is smooth
Guttate psoriasis: transient psoriatic rash frequently triggered by a streptococcal infection. Multiple red, teardrop lesions appear on the body
Pustular psoriasis: commonly occurs on the palms and soles

Question 6

Name some complications of psoriasis

Answer 6

Psoriatic arthropathy (around 10%)
Increased incidence of metabolic syndrome
Increased incidence of cardiovascular disease
Increased incidence of venous thromboembolism
Psychological distress

Question 7

What is the finger tip rule?

Answer 7

1 finger tip unit (FTU) = 0.5 g, sufficient to treat a skin area about twice that of the flat of an adult hand

Question 8

Name some moderate topical steroids

Answer 8

Betamethasone valerate 0.025% (Betnovate RD)

Clobetasone butyrate 0.05% (Eumovate)

Question 9

Name some clinical features of lichen planus

Answer 9

Itchy, papular rash most common on the palms, soles, genitalia and flexor surfaces of arms
Rash often polygonal in shape, with a ‘white-lines’ pattern on the surface (Wickham’s striae)
Koebner phenomenon may be seen (new skin lesions appearing at the site of trauma)
Oral involvement in around 50% of patients: typically a white-lace pattern on the buccal mucosa
Nails: thinning of nail plate, longitudinal ridging

Question 10

Which drugs can cause lichenoid drug eruptions

Answer 10

Gold
Quinine
Thiazides

Question 11

Name some causes of erythema nodosum

Answer 11

Infection:
Streptococci
Tuberculosis
Brucellosis
Systemic disease:
Sarcoidosis
Inflammatory bowel disease
Behcet's
Malignancy/lymphoma
Drugs:
Penicillins
Sulphonamides
Combined oral contraceptive pill
Pregnancy

Question 12

What is the cause of bullous pemphigoid?

Answer 12

Bullous pemphigoid is an autoimmune condition causing sub-epidermal blistering of the skin. This is secondary to the development of antibodies against hemidesmosomal proteins BP180 and BP230.

Question 13

What are the causes of SJS?

Answer 13

Penicillin
Sulphonamides
Lamotrigine, carbamazepine, phenytoin
Allopurinol
NSAIDs
Oral contraceptive pill

Question 14

Name some conditions associated with acanthosis nigricans

Answer 14

type 2 diabetes mellitus
gastrointestinal cancer
obesity
polycystic ovarian syndrome
acromegaly
Cushing’s disease
hypothyroidism
familial
Prader-Willi syndrome
drugs
combined oral contraceptive pill
nicotinic acid