Question 116#

A 67-year-old man is diagnosed with actinic keratoses on his right temple and prescribed fluorouracil cream. One week later he presents as the skin where he is applying treatment has become red and sore. On examination there is no sign of weeping or blistering.

What is the most appropriate action?

A. Continue fluorouracil cream + review in 1 week

Correct Answer A: This is a normal reaction to treatment. Fluorouracil should be continued for at least another week before starting topical steroids.

Actinic keratoses:
Actinic, or solar, keratoses (AK) is a common premalignant skin lesion that develops as a consequence of chronic sun exposure.

Features:

• Small, crusty or scaly, lesions
• May be pink, red, brown or the same colour as the skin
• Typically on sun-exposed areas e.g. temples of head
• Multiple lesions may be present 

Management options include:

• Prevention of further risk: e.g. sun avoidance, sun cream
• Fluorouracil cream: typically a 2 to 3 week course. The skin will become red and inflamed – sometimes topical hydrocortisone is given following fluorouracil to help settle the inflammation
• Topical diclofenac: may be used for mild AKs. Moderate efficacy but much fewer side-effects
• Topical imiquimod: trials have shown good efficacy
• Cryotherapy
• Curettage and cautery

Question 117#

A 19-year-old man is started on isotretinoin for severe nodulo-cystic acne.

Which one of the following side-effects is most likely to occur?

A. Low mood

Correct Answer E: Dry skin is the most common side-effect of isotretinoin.

Isotretinoin:

Isotretinoin is an oral retinoid used in the treatment of severe acne. Two-thirds of patients have a long term remission or cure following a course of oral isotretinoin.

Adverse effects:

• Teratogenicity: females should ideally be using two forms of contraception (e.g. Combined oral contraceptive pill and condoms)
• Dry skin, eyes and lips: the most common side-effect of isotretinoin
• Low mood
• Raised triglycerides
• Hair thinning
• Nose bleeds (caused by dryness of the nasal mucosa)
• Benign intracranial hypertension: isotretinoin treatment should not be combined with tetracyclines for this reason

Question 118#

Which one of the following statements regarding fungal nail infections is incorrect?

A. Candida accounts for less than 10% of cases

Correct Answer C: Onychomycosis is fungal infection of the nails.  

Fungal nail infections

This may be caused by:

• Dermatophytes - mainly Trichophyton rubrum, accounts for 90% of cases
• Yeasts - such as Candida
• Non-dermatophyte moulds

Features:

• 'unsightly' nails are a common reason for presentation
• Thickened, rough, opaque nails are the most common finding

Investigation:

• Nail clippings
• Scrapings of the affected nail

Management:

• Treatment is successful in around 50-80% of people
• Diagnosis should be confirmed by microbiology before starting treatment
• Dermatophyte infection: oral terbinafine is currently recommended first-line with oral itraconazole as an alternative. Six weeks - 3 months therapy is needed for fingernail infections whilst toenails should be treated for 3 - 6 months
• Candida infection: mild disease should be treated with topical antifungals (e.g. Amorolfine) whilst more severe infections should be treated with oral itraconazole for a period of 12 weeks

Onychomycosis caused by Trichophyton rubrum.

Question 119#

A 65-year-old woman with blistering lesions on her leg is diagnosed as having bullous pemphigoid.

What is the most appropriate initial management?

A. Reassurance

Correct Answer E: Bullous pemphigoid is an autoimmune condition causing sub-epidermal blistering of the skin. This is secondary to the development of antibodies against hemi-desmosomal proteins BP180 and BP230.

Bullous pemphigoid is more common in elderly patients. 

Bullous pemphigoid Features include:

• Itchy, tense blisters typically around flexures scarring
• The blisters usually heal without
• Mouth is usually spared* 

Skin biopsy:

• Immunofluorescence shows IgG and C3 at the dermoepidermal junction

Management:

• Referral to dermatologist for biopsy and confirmation of diagnosis
• Oral corticosteroids are the mainstay of treatment
• Topical corticosteroids, immunosuppressants and antibiotics are also used

*in reality around 10-50% of patients have a degree of mucosal involvement. It would however be unusual for an exam question to mention mucosal involvement as it is seen as a classic differentiating feature between pemphigoid and pemphigus. 

Question 120#

Each one of the following is associated with hypertrichosis, except:

A. Anorexia nervosa

Correct Answer C: hirsutism is often used to describe androgen-dependent hair growth in women, with hypertrichosis being used for androgen-independent hair growth.

Hirsutism and hypertrichosis:
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
• Ccosmetic 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, cyclosporin, diazoxide
• Congenital hypertrichosis lanuginosa, congenital hypertrichosis terminalis
• Porphyria cutanea tarda
• Anorexia nervosa

Facial hypertrichosis in porphyria cutanea tarda.

Congenital hypertrichosis lanuginosa.