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Medical arithmetic: unusual skin lesions on the hand, finger and arm



What do these presentations add up to? By Dr Keith Hopcroft

CASE EASY

The patient
An 18-month-old boy with no relevant past history, on no medication and up to date with all vaccinations.

His mother says
‘He’s been miserable with a fever for a couple of days. Now he’s got strange spots coming up. They’re mainly on his hands, with one or two on his feet. And it’s a nightmare trying to get any food or drink down him.’

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Hand_foot_mouth_disease_skin_lesions_on_hand

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See end of article for answer

CASE MODERATE

The patient
A 54-year-old man with no previous problems and on no medication.

He says
‘I keep getting this infection on my finger. There’s a small lump there most of the time. I squeeze stuff out of it but it keeps coming back. Is there any way to cure it once and for all?’

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Digital_myxoid_cyst

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See end of article for answer

CASE HARD

The patient
A 49-year-old man with no previous problems and no significant skin issues in the past.

He says
‘I’ve had this mark on my arm for a few months. It doesn’t cause me any bother but it seems to be getting a bit bigger and just looks odd. I spoke to the pharmacist about some cream but she said to get you to check it.’

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Amelanotic_malignant_melanoma_skin_cancer

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See end of article for answer


Dr Keith Hopcroft is Pulse’s medical adviser and a GP in Basildon, Essex


Answers
EASY Hand, foot and mouth disease This common viral illness mainly affects children. It has a prodrome of a few days of fever and malaise before the appearance, on hands and feet, of the characteristic small vesicles with surrounding erythema. There may be similar spots around the lips, but in the mouth the virus tends cause ulcers, which make eating and drinking painful. Treatment is symptomatic.
MODERATE Digital myxoid cyst These are ganglions at the distal interphalangeal joint or at the base of the nail. They can sometimes cause nail dystrophy, usually a longitudinal groove. Most cases require no treatment and some disappear spontaneously. Patients may assume they are an infection, often because they can squeeze ‘pus’ from them – actually the non-infective jelly-like cyst contents, which then tend to reaccumulate.
HARD Amelanocytic melanoma These are difficult to diagnose, as they lack the characteristic features of standard melanomas – in particular, pigment. Instead, they tend to be reddish or skin coloured papules or nodules that develop over weeks or months. They can mimic other skin lesions, benign and malignant. Consider this diagnosis if you see any evolving skin lesion that doesn’t fit the usual diagnostic categories.

Please note – these are all fictional cases and not based on any real patient interactions

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