Dermatology

OSCE Describing skin rashes and lesions Skin exam Explaining eczema and psoriasis Progress test Example questions Systemic associations

Where is it? Localised vs diffuse Symmetrical distribution Which body parts are affected?

What does it look like? Size Shape Edge (well- or poorly- demarcated) Colour (erythematous, pigmented)

<5mm >5mm Macule Skin patch Plaque Papule Nodule Vesicle Bulla Pustule Pustule

Associated with Crusting Scaling Lichenification Excoriation Surrounding skin?

Erythema ab igne Long term exposure to heat Heat packs, radiators Gets better once source of heat is removed

Impetigo Bacterial infection Staph aureus or strep pyogenes Often children 2-5 Contagious Treated with topical antibiotics, lasts about 3 weeks

Vitiligo Loss of pigment Multifactorial, probably immune related No cure, can be treated with UV light and steroid creams

Rosacea Long-term, unknown aetiology but may involve triggers such as alcohol, foods, menopause, stress Mild cases treated with cosmetics and avoiding triggers Medications: topical metronidazole, oral tetracyclines

Skin exam Expose patient to underwear (or say you would) Check skin systemically (top → bottom, arms → legs) Maintain dignity with a blanket If you see a rash or lesion, palpate and describe it Remember SONG Cover up patient, present findings To complete... take a history, use dermatoscope, systemic examinations, scrapes/biopsies

REAL PATIENTS??? Eczema Psoriasis ?other things you may see

Eczema “On the flexor surface, there is an erythematous, dry, scaly rash with multiple vesicles, associated with excoriation and lichenification. This is consistent with atopic eczema”

Psoriasis “On the extensor surface, there is a well-demarcated hyperkeratotic, scaly plaque with underlying erythema. This is consistent with plaque psoriasis”

Seborrheic keratosis Very common in older patients, NOT malignant, has a stuck on appearance.

Actinic keratosis Pre-malignant (SCC), due to sun exposure. Removed with 5-FU or cryotherapy

Naevi (moles) Benign, pigmented

Cherry angioma Occur in middle age, clusters of capillaries, numbers increase with age, benign

Acrochordon (skin tag) Benign, often on skin folds, benign

Dermatosis papulosa nigra Starts in adolescence, benign, occurs more in individuals with dark skin

Explaining eczema Water Immune cells

Explaining eczema

Fingertip units

Explaining psoriasis Top layer of skin Immune cells

Explaining psoriasis

A 22 year old woman comes into GP A 22 year old woman comes into GP. She has a 2 month history of weight loss and foul smelling stools. On examination you notice a symmetrical papulovesicular rash across her extensor surfaces with associated excoriation. Tissue transglutanimase antibodies are negative. What is the most likely underlying diagnosis? A. Inflammatory bowel disease B. Milk protein allergy C. ANCA vasculitis D. Coeliac disease E. Atopic eczema

D. Coeliac disease Rash is dermatitis herpetiformis

A 32 year old woman comes into GP with anxiety A 32 year old woman comes into GP with anxiety. On examination you see a p'eau d'orange rash on the shins. What is the most appropriate next investigation? A. Thyroid function tests B. Liver function tests C. Full blood count D. Urinalysis E. Spirometry

A. Thyroid function tests This is pretibial myxedema, which is associated with Graves disease

A 56 year old obese man comes into GP with frequent urination A 56 year old obese man comes into GP with frequent urination. On examination you see hyperpigmentation of the skin folds. What is the most likely diagnosis? Urinary tract infection Type 2 diabetes mellitus Vitiligo Psychogenic polydipsia Diuretic treatment

B. Type 2 diabetes mellitus This is acanthosis nigricans, which is associated with endocrine disorders such as type 2 diabetes, Cushing’s, PCOS and hypothyroidism

A nulliparous 24 year old woman comes into gynaecology clinic after three miscarriages over the last 2 years. On examination you see a lace patterned discoloration over the skin of her legs. What is the most likely diagnosis? A. Antiphospholipid syndrome B. Erythema ab igne C. Cervical incompetence D. Type 2 diabetes mellitus E. Graves disease

A. Antiphospholipid syndrome The rash is livedo reticularis, which is associated with APS, vasculitis and many other systemic conditions

A 30 year old woman comes into GP with frequent mouth ulcers, joint aches and fatigue. On examination of her face you notice a discoid erythematosus rash associated with crusting and scaling. She tells you this is worse on a sunny day. What is the most likely diagnosis? A. Inflammatory bowel disease B. Dermatophytosis (ringworm) C. Impetigo D. Discoid eczema E. SLE

E. SLE The rash is discoid lupus, which can be an isolated lupus (discoid lupus erythematosus) or associated with SLE

A 23 year old man comes to GP with a history of weight loss, abdominal pain, joint pain and diarrhoea. On examination you notice tender 3-5cm nodules on both legs. What is the most likely diagnosis? A. Hodgkins lymphoma B. Coeliac disease C. Inflammatory bowel disease D. Lynch syndrome E. Giardiasis

C. Inflammatory bowel disease The rash is erythema nodosum, and is associated with inflammatory bowel disease. Pyoderma gangrenosum is also associated with IBD