A 54-year-old woman with a history of type 1 diabetes mellitus presents with unsightly toenails affecting the lateral three nails of the left foot. On examination the nails and brown and break easily. Nail scrapings demonstrate Trichophyton rubrum infection.
What is the treatment of choice?
Correct Answer A: Dermatophyte nail infections - use oral terbinafine.
Fungal nail infections
Onychomycosis is fungal infection of the nails. This may be caused by:
Features:
Investigation:
Management:
Onychomycosis caused by Trichophyton rubrum.
Onychomycosis caused by Scopulariopsis brevicaulis.
Candida onychomycosis in a patient with chronic mucocutaneous candidosis.
A 81-year-old man is investigated after he develops a number of itchy blisters on his trunk. A skin biopsy suggests a diagnosis bullous pemphigoid.
This is most likely to be caused by antibodies directed against:
Correct Answer C: Bullous pemphigoid is an autoimmune condition causing sub-epidermal blistering of the skin. This is secondary to the development of antibodies against hemidesmosomal proteins BP180 and BP230 .
Bullous pemphigoid is more common in elderly patients.
Bullous pemphigoid Features include:
Skin biopsy:
*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.
Histopathology of bullous pemphigoid. Lesional skin biopsy with subepidermal splitting and a dense inflammatory infiltrate of eosinophils and neutrophils in the upper dermis.
Direct immunofluorescence microscopy of bullous pemphigoid. In a perilesional biopsy, linear binding of IgG at the dermal–epidermal junction is seen.
Classical bullous pemphigoid. Tense blisters and erosions on the arm, blisters arising on erythematous skin.
Classical bullous pemphigoid. Tense blisters and erosions on the hand, blisters arising on normal skin.
Classical bullous pemphigoid. Tense blisters and erosions on the gluteal region, blisters arising on erythematous skin.
Classic bullous pemphigoid. Tense blisters, erosions, and partly haemorrhagic crusts on back and left arm.
Classic bullous pemphigoid. Tense blisters, erosions, and partly haemorrhagic crusts on left hand.
A 60-year-old woman presents with a swelling just proximal to the nail bed on the left ring finger. She has a history of osteoarthritis but is usually well. On examination a 4mm, firm dome-shaped swelling is seen.
What is the most likely diagnosis?
Correct Answer D: Myxoid cysts (also known as mucous cysts) are benign ganglion cysts usually found on the distal, dorsal aspect of the finger.
There is usually osteoarthritis in the surrounding joint. They are more common in middle-aged women.
Myxoid cysts (A) Dermal erythema and swelling of the proximal nail folds with associated longitudinal groove of the nail plate. (B) Clear gelatinous fluid has drained from the index finger on the right (crusted site). Degenerative joint disease is present in both distal interphalangeal joints.
A 3-year-old girl is taken to her doctor due to a rash on the right upper arm. On examination multiple raised lesions of about 2 mm in diameter are seen. On close inspection a central dimple is present in the majority of lesions.
What is the likely diagnosis?
Correct Answer B: Molluscum contagiosum is caused by a pox DNA virus infection. It is typically seen in younger children and results in characteristic small, pearly, umbilicated lesions.
Molluscum contagiosum
Molluscum contagiosum is highly infectious.
Lesions may be present for up to 12 months and usually resolve spontaneously. Whilst various treatments may be effective in removing the lesions (e.g. surgery, cryotherapy, topical agents) no treatment is recommend in the initial phase due to the benign nature of the condition.
Molluscum contagiosum: typical pearly umbilicated papules on the trunk of a 12-month-old infant.
A 45-year-old man with a history of seborrhoeic dermatitis presents in late winter due a flare in his symptoms, affecting both his face and scalp.
Which one of the following agents is least likely to be beneficial?
Correct Answer E: There is less of a role for emollients in the management of seborrhoeic dermatitis than in other chronic skin disorders.
Seborrhoeic dermatitis in adults: Seborrhoeic dermatitis in adults is a chronic dermatitis thought to be caused by an inflammatory reaction related to a proliferation of a normal skin inhabitant, a fungus called Malassezia furfur (formerly known as Pityrosporum ovale). It is common, affecting around 2% of the general population.
Associated conditions include:
Scalp disease management:
Face and body management:
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