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

What are these presentations? By Dr. Keith Hopcroft

CASE EASY

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

His mother says
“He was miserable with a fever for a few days. Now he has some weird spots coming. They’re mostly on his hands, with one or two on his feet. And it’s a nightmare trying to get him to eat or drink.

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CASE MODERATE

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

He says
“I keep getting this infection on my finger. There is a small bump most of the time. I take things away from it but it keeps coming back. Is there a way to cure it once and for all?

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Digital_myxoid_cyst

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CASE HARD

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

He says
“I’ve had this mark on my arm for a few months. I don’t mind, but it seems to get a little bigger and looks weird. I talked to the pharmacist about a cream, but she told me to get you checked.

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Amelanotic_malignant_melanoma_cancer_of_the_skin

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Dr Keith Hopcroft is a Pulse Medical Advisor and GP in Basildon, Essex


Answers
EASY Hand-foot-mouth disease This common viral disease mainly affects children. He has a prodrome of a few days of fever and malaise before the appearance, on the hands and feet, of the characteristic small vesicles with surrounding erythema. There may be similar patches around the lips, but in the mouth the virus tends to cause ulcers, which makes eating and drinking painful. Treatment is symptomatic.
MODERATE Digital myxoid cyst These are nodes at the distal interphalangeal joint or at the base of the nail. They can sometimes cause nail dystrophy, usually a longitudinal groove. Most cases do not require treatment and some resolve on their own. Patients may assume it is an infection, often because they can extract ‘pus’ from it – effectively the non-infectious contents of the gelatinous cyst, which then tends to reaccumulate.
HARD Amelanocytic melanoma These are difficult to diagnose, as they lack the characteristics of standard melanomas – in particular, the pigment. Instead, they tend to be reddish or skin-colored papules or nodules that develop over weeks or months. They can mimic other skin lesions, both benign and malignant. Consider this diagnosis if you see an evolving skin lesion that does not fit the usual diagnostic categories.

Please note that these are fictitious cases and not based on real patient interactions

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