Dermatology

Question 1

ABCDE assessment of malignant melanoma

Answer 1

Asymmetry
Border irregularity (melanoma often has a ‘scalloped’ border)
Colour variation (a variegated lesion is one that consists of many colours)
Diameter >6mm
Evolves over time

Question 2

next step of management of any suspicious pigmented lesion

Answer 2

2-week wait referral to a dermatologist,

Question 3

Breslow thickness interpretation

Answer 3

Histology is used to diagnose melanoma and a Breslow thickness is established. The Breslow thickness is the depth of the tumour and is a strong predictor of outcome.

If the Breslow thickness is >1mm a sentinel node biopsy should be carried out, which can look for evidence of metastases and stage the cancer.

Question 4

Acne Rosacea

Answer 4

chronic skin condition causing flushing of the forehead, nose, cheeks and chin. The flushing can be transient, recurrent or persistent. It usually presents at age 30 to 60

rash consists of papules and pustules on an erythematous background, often with telangiectasia

rash made worse by sun exposure , hot weather, warm baths, stress and spicy foods.

Question 5

Acne Rosacea

management

Answer 5

General measures: camouflage creams, sun protection, avoiding factors causing facial flushing
1st line: topical antibiotics, such as Metronidazole (oral antibiotics can also be used if symptoms are more severe)
2nd line: other topical treatments such as Azelaic acid, Brimonidine or Ivermectin
Adjunct: an emollient can be used as a soap substitute to help improve symptoms if the skin is dry
Adjunct: laser therapy can be used to manage persistent telangiectasia

Question 6

Complications of untreated Rosacea include;

Answer 6

Rhinophyma, which describes skin thickening, enlargement and disfiguration of the nose

Ocular involvement such as blepharitis, conjunctivitis or keratitis

Question 7

Management of Acne Vulgaris depends on the severity

Answer 7

1st line (mild Acne) = topical Benzoyl Peroxide
2nd line (mild Acne) = topical antibiotic or topical retinoid
3rd line (moderate Acne) = oral antibiotic or oral anti-androgen (females only)
4th line (severe Acne) = oral retinoid

Question 8

Actinic Keratoses

Answer 8

thickened papules or plaques with surrounding erythematous skin and a keratotic, rough, warty surface. They are commonly found on sun exposed areas of skin, such as the backs of hands or the face.

Question 9

Actinic Keratoses RF

Answer 9

Type I or II skin (fair, burns easily)
History of sunburn
Outdoor occupation or hobbies
Immunosuppression

Question 10

Actinic Keratoses management

Answer 10

Localised lesions are managed using cryotherapy, curettage or surgical excision. Larger lesions are managed with topical therapies such as 5-Fluorouracil (a cytotoxic agent), a non-steroidal anti-inflammatory (NSAID) or Imiquimod (which modifies immune response).

Question 11

Causes of Non-Scarring Alopecia

Answer 11

Alopecia areata is an autoimmune disease where there are well-defined patches of hair loss. Surrounding hairs are narrower near the base and form characteristic ‘exclamation mark’ hairs. This usually reverses spontaneously after a few months

Telogen effluvium causes diffuse hair loss after severe physiological stress eg childbirth, illness, surgery.

Androgenic alopecia causes male- or female-pattern balding. In males it presents with a receding hairline and loss of hair on the vertex of the scalp. In females it presents with thinning of the hair.

Nutritional deficiencies and thyroid dysfunction may also cause non-scarring alopecia.

Question 12

Causes of Scarring Alopecia

Answer 12

Scarring alopecia is irreversible.

Folliculitis decalvans causes a scarring alopecia with perifollicular pustules (pustules around the base of follicles) and multiple hairs originating from a single follicle. It is thought to be due to infection with Staphylococcus aureus and so treatment is with oral antibiotics.

Lichen planopilaris is a form of lichen planus that causes patches of hair loss - cutaneous lichen planus is also usually seen.

Discoid lupus and tinea capitis may also cause scarring alopecia.

Question 13

The NICE criteria for diagnosing atopic dermatitis are itchy skin + 3/5 of:

Answer 13

Visible flexural eczema*
History of flexural eczema*
History of dry skin
History of asthma or allergic rhinitis (or history of atopy in 1st degree relative if <4 years)
Onset <2 years old (do not use if <4 years old)

Question 14

Management of a BCC

Answer 14

Surgical excision with a 4mm margin
Curettage and cautery
Mohs micrographic surgery if the BCC is in a cosmetically sensitive area or appears ill-defined. This involves examining the excised tissue under the microscope as it is removed to ensure all the cancerous cells are removed whilst preserving the maximum amount of healthy tissue.
Cryotherapy
Photodynamic therapy
Radiotherapy is used as an adjunct or if surgery is inappropriate
Topical therapies such as Imiquimod or 5-Fluorouracil

Question 15

Clinical Features of Arterial Ulcers

Answer 15

The ulcers usually have a punched-out appearance.
The ulcer and the surrounding skin are cold, white and shiny.
Other signs of peripheral arterial disease may be present such as intermittent claudication (pain on walking that is relieved by rest).
Pain may also occur at rest, usually at night when the legs are elevated and this is relieved by hanging feet off the end of the bed.
Peripheral pulses may be absent.

Question 16

Clinical Features of Venous Ulcers

Answer 16

Ulcers are usually above the medial malleolus, are shallow, exudative and warm.
Other signs of venous insufficiency may be present such as ankle swelling, varicose veins, haemosiderin deposition, venous eczema and lipodermatosclerosis.

Question 17

Tuberous sclerosis

Answer 17

autosomal dominant disease of incomplete penetrance. It results in formations of hamartomas, a type of benign tumour, all over the body.

Clinical Features
The skin is usually affected and signs include:

Angiofibromas: dome-shaped, firm papules in a butterfly distribution across the face.
Ashleaf macules: oval patches of white/hypopigmented skin
Shagreen patch: leathery plaque on the sacrum that is dimpled like orange peel
Ungal fibromas: smooth, fleshy tumours that grow from the nail folds either around the nail or under the nail

Question 18

Cutaneous features of Type I Neurofibromatosis

Answer 18

Cafe-au-lait spots
These are oval shaped, coffee-coloured patches that continue to grow throughout life.
Whilst they can sometimes be a benign feature in healthy people, having 6 macules >5mm (of >15mm if post-pubertal) is a feature of NF1.
Axillary or inguinal freckling
Neurofibromas of any type. These are small nodular tumours in the skin.

Question 19

Type 2 Neurofibromatosis

Answer 19

Type 2 neurofibromatosis (NF2) is a related disorder that results in bilateral vestibular schwannomas (acoustic neuromas) resulting in a triad of sensorineural hearing loss, tinnitus and vertigo.

Cafe-au-lait spots may also be present.

Question 20

Features of limited systemic sclerosis

CREST

Answer 20

The scleroderma in limited systemic sclerosis is limited to the hands/feet/face.
It is also called CREST syndrome which stands for Calcinosis, Raynaud’s, oEsophageal dysmotility, Sclerodactyly and Telangiectasia.
Raynaud’s is where spasm of arteries in the hands reduce blood flow to the fingers, causing the fingertips to turn white/blue and become numb- this usually occurs in the cold.
Sclerodactyly is the hardening and tightness of the skin of the fingers and the tips of the fingers appear to curl inwards slightly resulting in the recognisable clawed appearance. This tightening of the skin (scleroderma) can also affect the face, resulting in a ‘beak-shaped’ nose and microstomy (reduced aperture of the mouth).
Telangiectasia usually affects the hands and lips. In addition to cutaneous features, limited systemic sclerosis can also cause pulmonary hypertension.
Investigations of limited systemic sclerosis
Anti-centromere antibodies are positive in 80%.

Question 21

Diffuse Systemic Sclerosis features

Answer 21

Diffuse Systemic Sclerosis features
Diffuse systemic sclerosis can affect any part of the body and also affects visceral organs. It is much more severe and can cause lung, heart and renal involvement.

Diffuse Systemic Sclerosis antibodies
Anti-topoisomerase-1 (Scl-70) and anti-RNA polymerase antibodies may be present.

Question 22

Common causes of an urticarial eruption include:

Answer 22

NSAIDs
Beta-lactam antibiotics
Opiates
ACE-inhibitors

Question 23

Morbilliform Eruption

Answer 23

IV T cell mediated hypersensitivity reaction and so there is a delay of 1-2 weeks between starting the drug and the rash.

Amoxicillin - especially if the patient is also infected with EBV (glandular fever)
Beta-lactam antibiotics
Sulphonamides
Allopurinol

Question 24

Causes of Lichenoid Eruption

Answer 24

Lichenoid eruptions present with purple, pruritic, polygonal, planar papules/plaques.
Longitudinal ridging may be seen in the nails but the oral mucosa is not usually affected.
Typically a lichenoid eruption occurs 2 months after starting a medication.

Causes of Lichenoid Eruption
Common causes include:

B-blockers
Thiazides
ACE-i
Antimalarials
Gold
Penicillamine

Question 25

Causes of erythema nodosum (NODOSUM):

Answer 25

NO cause (idiopathic in 50%)
Drugs: sulfonamides, dapsone
OCP
Sarcoidosis
Ulcerative colitis/Crohn's
Micro: Tuberculosis, Streptococcus, Toxoplasmosis

Question 26

Henoch-Schonlein purpura (HSP)

Answer 26

classical triad of purpura over the extensor surfaces of the lower limb, abdominal pain and arthritis.

Question 27

Impetigo

Answer 27

Clinical features
It classically presents as a pruritic rash with discrete patches that have a golden crusting
Patients may also be febrile
It commonly occurs in infants and school-age children
Management
In most circumstances it can be managed in primary care with topical treatments such as fusidic acid. Oral flucloxacillin may also help.
It is highly infectious. Patients should not share towels and should not attend school or work until they have completed 48 hours of antibiotic treatment

Question 28

Risk factors for developing a Keloid scar include;

Answer 28

Darker skin, especially those of African, Hispanic or Chinese ethnicity
Age between puberty and 30 years old
Previous history of a Keloid scar

Question 29

Lichen planus

Answer 29

Cutaneous lichen planus is characterised by the 6 Ps:

Purple
Pruritic (itchy)
Polygonal (multiple sides)
Planar (flat-topped)
Papules/plaques

Question 30

Pemphigus Vulgaris

Answer 30

n fragile, superficial blisters that rupture easily and de-squamation; Nikolsky sign is positive.
Mucosa may be affected and the oral mucosa is almost always affected.

skin biopsy and immunofluorescence which shows deposition of IgG auto-antibodies within the epidermis.
This results in the characteristic ‘chicken-wire’ or ‘crazy-paving’ appearance.

Question 31

Pityriasis rosea

Answer 31

Pityriasis rosea is a common rash which often occurs after an upper respiratory tract infection and is thought to have a viral cause (HHV 6/7).

Clinical Features
It is characterized by a preceding herald patch - a single, large, discoid (coin-shaped), erythematous patch. This patch classically has a ‘collarette’ of scale just inside the edge of the lesion.

Question 32

scabies managament

Answer 32

Management
The first line management of scabies is topical permethrin 5%.
Malathion 0.5% should be used 2nd line as there is limited evidence for its effectiveness.
To minimise chance of reinfection it is very important that all contacts, included members from the same household, are treated on the same day.

Question 33

Acquired melanocytic naevus

Answer 33

Junctional: flat + pigmented (due to melanocytes at the basal layer of the epidermis)
Compound: raised + pigmented (due to melanocytes at the basal layer of the epidermis + deep in the dermis)
Intradermal: raised + pale (due to melanocytes deep in the dermis)