Dermatology

Question 1

Shin lesions - examples

Answer 1

• erythema nodosum
• pretibial myxoedema
• pyoderma gangrenosum
• necrobiossi lipoidica diabeticorum

Question 2

Features of eythema nododsum

Answer 2

• symmetrical, erythematous, tender, nodules which heal without scarring
• most common causes are streptococcal infections, sarcoidosis, inflammatory bowel disease and drugs (penicillins, sulphonamides, oral contraceptive pill)
• commonly on shins but can also occur on forearms and thighs

Question 3

Features of pretibial myoxoedema

Answer 3

• symmetrical, erythematous lesions seen in Graves’ disease

- shiny, orange peel skin

Question 4

Features of pyoderma gangrenosum

Answer 4

• initially small red papule
• later deep, red, necrotic ulcers with a violaceous border
• idiopathic in 50%, may also be seen in inflammatory bowel disease, connective tissue disorders and myeloproliferative disorders

Question 5

Features of necrobiosis lipoidica dibeticorum

Answer 5

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

Question 6

What is leukoplakia?

Answer 6

• premalignant condition which present as white, hard spots on the mucous membranes of the mouth

Question 7

Treatment for dermarophyte nail inections

Answer 7

Oral terbinafine

Question 8

Rare but important side effect of pencillins

Answer 8

Toxic epidermal necrolysis/ Steven Johnson syndrome

Question 9

Pityriasis rosea

Answer 9

Resolve 6-12 weeks

Question 10

Pemphigus vulgaris

Pathiphysiology

Answer 10

Autoimmune disease causing antibodies directed against desmosomes

Question 11

First line management for plaque psoriasis

Answer 11

Topical potent corticosteroids
E.g. topical betamethasone valerate

*topical vit D is 2nd line if no improvement after 8 weeks

Question 12

Scabies - defining presentation

Answer 12

Silver burrows present in the interdigital folds and intensely pruritic rash which is worse at night

• spread skin to skin contact
• treat with permethrin

Question 13

Crusted norwegian scabies

Answer 13

• seen in patients with surpresses immunity especailly HIV
• ivermectin treatment of choice
• isolation is essential

Question 14

Seborrhoeic dermatitis

Answer 14

Inflammtory reaction related to proliferation of a normal skin inhabitant, a fungus called Malassezia furfur

• topical antifungals: ketoconazole

Question 15

Bowen’s disease

Answer 15

• precancerous dermatosis is a precursor to squamous cell carcinoma
• 5-10% chance of becoming malignant
• red, scaly patches