Question 21#

Which one of the following complications is most associated with psoralen + ultraviolet A light (PUVA) therapy?

A. Squamous cell cancer

Correct Answer A: The most significant complication of PUVA therapy for psoriasis is squamous cell skin cancer.

Psoriasis: management:
SIGN released guidelines in 2010 on the management of psoriasis and psoriatic arthropathy. Please see the link for more details. 

Chronic plaque psoriasis:

• Regular emollients may help to reduce scale loss and reduce pruritus
• For acute control SIGN recommend: 'Short term intermittent use of a potent topical corticosteroid or a combined potent corticosteroid plus calcipotriol ointment is recommended to gain rapid improvement in plaque psoriasis.'
• 'For long term topical treatment of plaque psoriasis a vitamin D analogue (e.g. Calcipotriol) is recommended.'
• 'If a vitamin D analogue is ineffective or not tolerated then consider coal tar (solution, cream or lotion), tazarotene gel, or short contact dithranol (30 minute exposure in patients with a small number of relatively large plaques of psoriasis).

Steroids in psoriasis:

• Topical steroids are commonly used in flexural psoriasis and there is also a role for mild steroids in facial psoriasis. If steroids are ineffective for these conditions vitamin D analogues or tacrolimus ointment should be used second line
• SIGN caution against the long term use of potent or very potent topical steroids due to the risk of side effects 

Scalp psoriasis:

• For short term control SIGN recommend either the use of potent topical corticosteroids or a combination of a potent corticosteroid and a vitamin D analogue.
• 'For patients with thick scaling of the scalp, initial treatment with overnight application of salicylic acid, tar preparations, or oil preparations (eg olive oil, coconut oil) to remove thick scale is recommended. 

Secondary care management:

Phototherapy:

• Narrow band ultraviolet B light (311-313nm) is now the treatment of choice
• Photochemotherapy is also used - psoralen + ultraviolet A light (PUVA)
• Adverse effects: skin aging, squamous cell cancer (not melanoma)

Systemic therapy:

• Methotrexate: useful if associated joint disease
• Ciclosporin
• Systemic retinoids
• Biological agents: infliximab, etanercept and adalimumab
• Ustekinumab (IL-12 and IL-23 blocker) is showing promise in early trials

Mechanism of action of commonly used drugs:

• Coal tar: probably inhibit DNA synthesis
• Calcipotriol: vitamin D analogue which reduces epidermal proliferation and restores a normal horny layer
• Dithranol: inhibits DNA synthesis, wash off after 30 mins, SE: burning, staining

Question 22#

A 38-year-old woman with a history of rheumatoid arthritis and epilepsy presents with generalized increased hair growth over her trunk and arms.

Which one of the following drugs is associated with hypertrichosis?

A. Sodium valproate

Correct Answer D: Phenytoin is associated with hirsutism rather than hypertrichosis.

Hirsutism and hypertrichosis:
Hirsutism is often used to describe androgen-dependent hair growth in women, with hypertrichosis being used for androgen-independent hair growth.

Polycystic ovarian syndrome is the most common causes of hirsutism.

Other causes include:

• Cushing's syndrome
• Congenital adrenal hyperplasia
• Androgen therapy
• Obesity: due to peripheral conversion oestrogens to androgens
• Adrenal tumour
• Androgen secreting ovarian tumour
• Drugs: phenytoin

Assessment of hirsutism:

• Ferriman-Gallwey scoring system: 9 body areas are assigned a score of 0 - 4, a score > 15 is considered to indicate moderate or severe hirsutism 

Management of hirsutism:

• Advise weight loss if overweight
• Cosmetic techniques such as waxing/bleaching - not available on the NHS
• Consider using combined oral contraceptive pills such as co-cyprindiol (Dianette) or ethinylestradiol and drospirenone (Yasmin). Co-cyprindiol should not be used long-term due to the increased risk of venous thromboembolism
• Facial hirsutism: topical eflornithine - contraindicated in pregnancy and breast-feeding

Causes of hypertrichosis:

• Drugs: minoxidil, ciclosporin, diazoxide
• Congenital hypertrichosis lanuginosa, congenital hypertrichosis terminalis
• Porphyria cutanea tarda
• Anorexia nervosa

Ferriman–Gallwey hirsutism scoring system. Each of the nine body areas most sensitive to androgen
is assigned a score from 0 (no hair) to 4 (frankly virile). The numbers in each area are added to obtain the total
score. A score of 6 to 8 generally defines hirsutism.

Question 23#

A 64-year-old patient is referred to dermatology outpatients due to a rash. A diagnosis necrolytic migratory erythema is made.

What is the most likely underlying diagnosis? 

A. Gastrinoma

Correct Answer C: Glucagonoma is associated with Necrolytic Migratory Erythema.

Skin disorders associated with malignancy

Paraneoplastic syndromes associated with internal malignancies:

Necrolytic migratory erythema in the groin area.

Question 24#

A 31-year-old woman develops with painful, purple lesions on her shins.

Which one of the following medications is most likely to be responsible?

A. Montelukast

Correct Answer C: 

Erythema nodosum

Overview:

• Inflammation of subcutaneous fat
• Typically causes tender, erythematous, nodular lesions
• Usually occurs over shins, may also occur elsewhere (e.g. forearms, thighs)
• Usually resolves within 6 weeks
• Lesions heal without scarring

Causes:

• Infection: streptococci, TB, brucellosis
• Systemic disease: sarcoidosis, inflammatory bowel disease, Behcet's
• Malignancy/lymphoma
• Drugs: penicillins, sulphonamides, combined oral contraceptive pill
• Pregnancy

Erythema nodosum. Red, node-like swelling in the characteristic distribution.

Question 25#

Which one of the following conditions is least likely to be associated with pyoderma gangrenosum?

A. Ulcerative colitis

Correct Answer B: Syphilis is not commonly associated with pyoderma gangrenosum.

Pyoderma gangrenosum

Features:

• Typically on the lower limbs
• Initially small red papule
• Later deep, red, necrotic ulcers with a violaceous border
• May be accompanied systemic symptoms e.g. Fever, myalgia

Causes*:

• Idiopathic in 50%
• Inflammatory bowel disease: ulcerative colitis, Crohn's
• Rheumatoid arthritis, SLE
• Myeloproliferative disorders
• Lymphoma, myeloid, Leukaemias
• Monoclonal gammopathy (IgA)
• Primary biliary cirrhosis

Management:

• The potential for rapid progression is high in most patients and most doctors advocate oral steroids as first-line treatment
• Other immunosuppressive therapy, for example ciclosporin and infliximab, have a role in difficult cases

*Note whilst pyoderma gangrenosum can occur in diabetes mellitus it is rare and is generally not included in a differential of potential causes

Pyoderma gangrenosum. Lesions begin as a vesiculopustular that forms an ulcer with deep violaceous overhanging or undermined borders.