A 34-year-old man with a history of polyarthralgia, back pain and diarrhoea is found to have a 3 cm red lesion on his shin which is starting to ulcerate.
What is the most likely diagnosis?
Correct Answer E: This patient is likely to have ulcerative colitis, which has a known association with large-joint arthritis, sacroiliitis and pyoderma gangrenosum.
Pyoderma gangrenosum: Features:
Causes*:
Management:
*note whilst pyoderma gangrenosum can occur in diabetes mellitus it is rare and is generally not included in a differential of potential causes.
A 33-year-old is investigated for lethargy. The full blood count is reported as follows:
His daughter was unwell one week previously with a pyrexial illness associated with a red rash on her cheeks.
What is the most likely cause?
Correct Answer D: Parvovirus B19 is a DNA virus which causes a variety of clinical presentations. It was identified in the 1980's as the cause of erythema infectiosum.
Parvovirus B19
Erythema infectiosum (also known as fifth disease or 'slapped-cheek syndrome'):
Other presentations:
Parvovirus, erythema infectiosum (fifth disease).On day 1, warm, erythematous, nontender, circumscribed patches appear over the cheeks.
Parvovirus, erythema infectiosum (fifth disease). On day 1, warm, erythematous, nontender, circumscribed patches appear over the cheeks (above). These fade on the next day, as an erythematous, lacy rash develops on the extensor surfaces of the extremities.
Which one of the following is least likely to cause a bullous rash?
Correct Answer C: The bullous variant of lichen planus is extremely rare.
Bullous disorders:
Causes of skin bullae:
A 64-year-old female is referred to dermatology due to a non-healing skin ulcer on her lower leg. This has been present for around 6 weeks and the appearance didn't improve following a course of oral flucloxacillin.
What is the most important investigation to perform first?
Correct Answer C: An ankle-brachial pressure index measurement would help exclude arterial insufficiency as a contributing factor.
If this was abnormal then a referral to the vascular surgeons should be considered.
If the ulcer fails to heal with active management (e.g. Compression bandaging) then referral for consideration of biopsy to exclude a malignancy should be made.
Ongoing infection is not a common cause of non-healing leg ulcers.
Venous ulceration:
Venous ulceration is typically seen above the medial malleolus.
Investigations:
A 33-year-old woman is reviewed in the dermatology clinic with patchy, well demarcated hair loss on the scalp. This is affecting around 20% of her total scalp, and causing significant psychological distress. A diagnosis of alopecia areata is suspected.
Which one of the following is an appropriate management plan?
Correct Answer D: Watchful waiting for spontaneous remission is another option. Neither the British Association of Dermatologists or Clinical Knowledge Summaries recommend screening for autoimmune disease.
Alopecia areata:
Alopecia areata is a presumed autoimmune condition causing localised, well demarcated patches of hair loss. At the edge of the hair loss, there may be small, broken 'exclamation mark' hairs.
Hair will regrow in 50% of patients by 1 year, and in 80-90% eventually. Careful explanation is therefore sufficient in many patients.
Other treatment options include:
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