A 23-year-old man presents with a three day history of general malaise and low-grade temperature. Yesterday he developed extensive painful ulceration of his mouth and gums. On examination his temperature is 37.4ºC, pulse 84 / min and there is submandibular lymphadenopathy.
What is the most likely diagnosis?
Correct Answer D: This man has gingivostomatitis, a characteristic feature of primary herpes simplex virus infection.
Herpes simplex virus:
There are two strains of the herpes simplex virus (HSV) in humans:
HSV-1 and HSV-2. Whilst it was previously thought HSV-1 accounted for oral lesions (cold sores) and HSV-2 for genital herpes it is now known there is considerable overlap.
Features:
Management:
Primary herpetic gingivostomatitis: multiple ulcers on the tongue.
Primary herpetic gingivostomatitis: erythema and multiple ulcers on the gingiva.
Which one of the following conditions is most strongly associated with erythema multiforme?
Correct Answer D: This is difficult as both herpes simplex and streptococcal infections are known causes of erythema multiforme (EM). However, studies suggest that HSV is the trigger in over 50% of cases. Streptococcal infections and sarcoidosis are more strongly associated with erythema nodosum.
Erythema multiforme:
If symptoms are severe and involve blistering and mucosal involvement the term Stevens-Johnson syndrome is used.
Causes:
*Orf is a skin disease of sheep and goats caused by a parapox virus
Target lesions in erythema multiforme.
Orf with erythema multiforme. The orf lesion on the dorsum of the forefinger has been present for 14 days; the secondary erythema multiforme for 4 days.
Which of the following conditions is most associated with onycholysis?
Correct Answer B: Raynaud's disease causes onycholysis, as can any cause of impaired circulation.
Onycholysis:
Onycholysis describes the separation of the nail plate from the nail bed.
Coarse, irregular pits on the nail plate surface. Onycholysis with salmon-colored border can be appreciated in the ring finger.
A 34-year-old man presents for the removal of a mole.
Where on the body are keloid scars most likely to form?
Correct Answer A: Keloid scars are most common on the sternum.
Keloid scars:
Keloid scars are tumour-like lesions that arise from the connective tissue of a scar and extend beyond the dimensions of the original wound.
Predisposing factors:
Keloid scars are less likely if incisions are made along relaxed skin tension lines*
Treatment:
*Langer lines were historically used to determine the optimal incision line. They were based on procedures done on cadavers but have been shown to produce worse cosmetic results than when following skin tension lines.
Ear keloid. This keloid failed to respond to intralesional triamcinolone. The lesion was excised.
Keloids form in predisposed individuals following cystic acne.
A 45-year-old woman presents for review. She has noticed a number of patches of 'pale skin' on her hands over the past few weeks. The patient has tried using an emollient and topical hydrocortisone with no result. On examination you note a number of hypopigmented patches on the dorsum of both hands. Her past medical history includes thyrotoxicosis for which she takes carbimazole and thyroxine.
What is the most likely causes of her symptoms?
Correct Answer A: Vitiligo is more common in patients with known autoimmune conditions such as thyrotoxicosis. There is nothing else in the history to suggest Addison disease.
Vitiligo is an autoimmune condition which results in the loss of melanocytes and consequent depigmentation of the skin. It is thought to affect around 1% of the population and symptoms typically develop by the age of 20-30 years.
Associated conditions:
Vitiligo. The back of the hand is a commonly involved site.
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