Dermatology

Question 1

Classic presentation of dermatitis herpetiformis

Answer 1

itchy papules and vesicles on extensor surfaces

Question 2

diagnosis of dermatitis herpetiformis

Answer 2

immunoflorescence shows IgA deposits in the upper dermis

Question 3

Management of dermatitis herpetiformis

Answer 3

gluten free diet

dapsone

Question 4

acne rosacea treatment

Answer 4

mild/moderate - topical metronidazole

severe/resistant - oral tetracycline

Question 5

features of acne rosacea:

where it affects, type of lesions

Answer 5

cheek face and forehead
initially flushing , telangectesia are common,
later develops into persistent erythema with papules and pustules
can lead to rhinophyma, and my have blepharitis

Question 6

causes of erythema multiforme

Answer 6

• viruses: HSV (in 50% of cases), Orf (parapox virus)
• idiopathic
• bacteria: Mycoplasma, Streptococcus
• drugs: penicillin, sulphonamides, carbamazepine, allopurinol, NSAIDs, OCP, nevirapine
• connective tissue disease e.g. SLE
• sarcoidosis
• malignancy

Question 7

features of erythema multiforme

Answer 7

target lesions
usually start on backs of hands/feet then spread to torso
more commonly upper limbs than lower limbs
mild pruritis

Question 8

Definition of onycholysis

Answer 8

separation of the nail plate from the nail bed

Question 9

Causes of onycholysis

Answer 9

trauma
infection esp fungal
skin disease eg psoriasis, dermatitis
impaired circulation eg Raynauds
hypo/hyper-thyroidism

Question 10

define keyloid scar

Answer 10

tumour-like growth originating from connective tissue of a scar and extend beyond the border of the original wound

Question 11

Risk factors for a keyloid scar

Answer 11

young
afrocarribean
common sites (most common first): sternum, shoulder, neck, face, extensor surfaces, trunk

Question 12

Vitiligo:

• aeteology
• age of onset
• features

Answer 12

autoimmune loss of melanocytes –> hypopigmentation
1% of population, starts in 20-30s
well demarcated patches of depigmented skin, usually peripheries, trauma may precipitate new lesions (Koebner phenomenon)

Question 13

Vitiligo associated conditions

Answer 13

T1DM
Addisons disease,
Autoimmune thyroid disorders,
Pernicious anaemia,
Alopecia areata

Question 14

Management of vitiligo

Answer 14

sun block

topical steriods if applied early

Question 15

Main complication of PUVA therapy for psoriasis

Answer 15

SCC

Question 16

features of pyoderma gangrenosum

Answer 16

small papule ->deep red necrotic ulcer with violaceous border (gun metal grey)
typically on lower legs
may have systemic upset (fever, myalgia)

Question 17

causes of pyoderma gangrenosum

Answer 17

idiopathic
IBD 
RA, SLE
myeloproliferative disorders
lymphoma, myeloid leukaemias
monoclonal gammopathy (IgA)
primary biliary cirrhosis (DR3)

Question 18

Mx of pyoderma gangrenosum

Answer 18

oral steroids +/- other immunosuppressants (eg infliximab)

Question 19

Acanthosis nigricans disease associations

Answer 19

endo: diabetes mellitus, Cushing's disease, hypothyroid, acromegaly
UC
gastric cancers
PCOS
obesity
Prader-Willi syn
drugs: OCP, nicotinic acid

Question 20

features and pathology of lichen sclerosus

Answer 20

inflammation of epidermis of genitals leads to atrophy and formation of itchy white plaques.
More common in elderly females

Question 21

Mx of lichen sclerosus

Answer 21

biopsy to exclude other conditions (increased risk of vulval cancer)
topical steroids and emollients

Question 22

features of lichen planus

Answer 22

purple papules that are pruritic
white cracks over the top (Wickham’s striae)
oral involvement common.

Question 23

features of toxic epidermal necrolysis?

commonly due to

Answer 23

scalded appearance with friable epidermis
systemic upset - pyrexia, tachycardia
most commonly due to a drug reaction (penicillin, phenytoin, allopurinol, carbamazepine)

Question 24

common drug precipitants of TEN?

Answer 24

phenytoin,
allopurinol
penicillins
carbamazepine

Question 25

causes of scarring alopecia

Answer 25

trauma, burns, radiotherapy
lichen planus
discoid lupus
tinea capitis (if a kerion develops)

Question 26

causes of non-scarring alopecia

Answer 26

male pattern baldness
drugs: cytotoxic, carbimazole, heparin, OCP, colchicine
nutritional:iron and zinc def
autoimmune: alopecia areata
telogen effluvium (hair loss following stressful time)
trichotillomania (pulling hair out)

Question 27

classical features of pretibial myxoedema

Answer 27

symmetrical erythematous shin lesions with shiny orange peel skin
seen in Graves disease

Question 28

classical features of Necrobiosis lipoidica diabeticorum

Answer 28

shiny, painless areas of yellow/red skin typically on the shin of diabetics
often associated with telangiectasia

Question 29

Exacerbating factors for psoriasis

Answer 29

withdrawal of steroids
trauma
alcohol
beta blockers, lithium, NSAIDS, ACEi, antimalarials

Question 30

Features of bullous pemphigoid

Answer 30

Itchy tense blisters, typically around flexures
Blisters heal without scarring
Rarely involves mucous membranes (NB differentiating feature with pemphigus)

Question 31

Ix and Mx of bullous pemphigoid

Answer 31

Skin biopsy - IgG and C3 deposits at dermoepidermal junction

Oral corticosteroids

Question 32

What are myxoid cysts and where are they usually found?

Associations?

Answer 32

Benign ganglion cysts on the dorsum of a distal phalanx
Usually have OA in surrounding joint
In middle aged females

Question 33

Complications of psoriasis

Answer 33

Psoriatic arthritis
Superimposed bacterial infection
Metabolic syndrome
Cardiovascular disease
VTE

Question 34

Pathology of bullous pemphigoid

Answer 34

Autoantibodies against hemidesmosomal proteins BP180 and BP230

Question 35

Features of drug hypersensitivity syndrome

Mx

Answer 35

3-6 weeks after starting anticonvulsants or antimicrobials
fever, facial oedema, papulopustular rash, lymphadenopathy or hepatitis
associated eosinophilia
Rx with oral steroids

Question 36

Association of necrolytic migratory erythema

Answer 36

glucagonoma