Question 1#

A 41-year-old man develops itchy, polygonal, violaceous papules on the flexor aspect of his forearms. Some of these papules have coalesced to form plaques.

What is the most likely diagnosis?

A. Lichen planus

Correct Answer A: Lichen

• Planus: purple, pruritic, papular, polygonal rash on flexor surfaces. Wickham's striae over surface. Oral involvement common
• Sclerosis: itchy white spots typically seen on the vulva of elderly women

Lichen Planus:

Lichen planus is a skin disorder of unknown aetiology, most probably being immune mediated

Features:

• Itchy, papular rash most common on the palms, soles, genitalia and flexor surfaces of arms
• Rash often polygonal in shape, 'white-lace' 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
• Nails: thinning of nail plate, longitudinal ridging

Lichenoid drug eruptions - causes:

• Gold
• Quinine
• Thiazides

Management:

• Topical steroids are the mainstay of treatment
• Extensive lichen planus may require oral steroids or immunosuppression

The basic lesion is a firm reddishviolet polygon. The surface, which has a sheen in oblique illumination, is covered with fine greyish striations known as Wickham's striae.

Papules may appear along the excoriations caused by scratching (Koebner's phenomenon).

Question 2#

A 30-year-old female in her third trimester of pregnancy mentions during an antenatal appointment that she has noticed an itchy rash around her umbilicus. This is her second pregnancy and she had no similar problems in her first pregnancy. Examination reveals blistering lesions in the peri-umbilical region and on her arms.

What is the likely diagnosis?

A. Seborrhoeic dermatitis

Correct Answer E: Polymorphic eruption of pregnancy is not associated with blistering. Pemphigoid gestationis is the correct answer. Polymorphic eruption of pregnancy is not associated with blistering.

Skin disorders associated with pregnancy:

1- Polymorphic eruption of pregnancy:

• Pruritic condition associated with last trimester
• Lesions often first appear in abdominal striae
• Management depends on severity: emollients, mild potency topical steroids and oral steroids may be used

2- Pemphigoid gestationis:

• Pruritic blistering lesions
• Often develop in peri-umbilical region, later spreading to the trunk, back, buttocks and arms
• Usually presents 2nd or 3rd trimester and is rarely seen in the first pregnancy
• Oral corticosteroids are usually required 

Pemphigoid gestationis Erythematous urticarial and few tense vesicles, notice the periumbilical involvement.

Question 3#

A 62-year-old female is referred to dermatology due to a lesion over her shin. It initially started as a small red papule which later became a deep, red, necrotic ulcer with a violaceous border.

What is the likely diagnosis?

A. Necrobiosis lipoidica diabeticorum

Correct Answer E: This is a classic description of Pyoderma Gangrenosum skin lesions.

The differential diagnosis of shin lesions includes the following conditions:

• Erythema nodosum
• Pretibial myxoedema
• Pyoderma gangrenosum
• Necrobiosis lipoidica diabeticorum

Below are the characteristic features: 

Erythema nodosum:

• 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)

Pretibial myxoedema:

• Symmetrical, erythematous lesions seen in Graves' disease
• Shiny, orange peel skin 

Pyoderma gangrenosum:

• 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

Necrobiosis lipoidica diabeticorum:

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

Pyoderma gangrenosum The initial lesion is a rapidly enlarging hemorrhagic nonfollicular pustule surrounded by an erythematous halo and is very painful.

Pyoderma gangrenosum Lesions rapidly break down in the center and become boggy, hemorrhagic, and purulent ulcers.

Question 4#

A 39-year-old female has a pigmented mole removed from her leg which histology shows to be a malignant melanoma.

What is the single most important prognostic marker?

A. Number of episodes of sunburn before the age of 18 years

Correct Answer D: Melanoma: the invasion depth of the tumour is the single most important prognostic factor.

Malignant melanoma: prognostic factors:

The invasion depth of a tumour (Breslow depth) is the single most important factor in determining prognosis of patients with malignant melanoma.

Black, blue, grey and white in a malignant melanoma.

Halo phenomenon developing within a malignant melanoma that later proved fatal.

Question 5#

A 62-year-old female is referred due to a long-standing ulcer above the right medial malleolus. Ankle-brachial pressure index readings are as follows:

To date it has been managed by the District Nurse with standard dressings.

What is the most appropriate management to maximize the likelihood of the ulcer healing?

A. Compression bandaging

Correct Answer A: Management of venous ulceration - compression bandaging.

The ankle-brachial pressure index readings indicate a reasonable arterial supply and suggest the ulcers are venous in nature. 

Venous ulceration: Venous ulceration is typically seen above the medial malleolus.

Investigations:

• Ankle-brachial pressure index (ABPI) is important in non-healing ulcers to assess for poor arterial flow which could impair healing
• A 'normal' ABPI may be regarded as between 0.9 - 1.2. Values below 0.9 indicate arterial disease. Interestingly, values above 1.3 may also indicate arterial disease, in the form of false-negative results secondary to arterial calcification (e.g. In diabetics)

Management:

• Compression bandaging, usually four layer (only treatment shown to be of real benefit)
• Oral pentoxifylline, a peripheral vasodilator, improves healing rate
• Small evidence base supporting use of flavinoids
• Little evidence to suggest benefit from hydrocolloid dressings, topical growth factors, ultrasound therapy and intermittent pneumatic compression

Venous Ulcer.

Same patient after few weeks of compression bandaging.