Frank, a 20-year-old tennis coach, attends his GP regarding a recently discovered skin lesion on his right foot. He rarely checks his skin and only noticed this lesion within the past two weeks. He does not feel it has changed since he noticed it and reports it is neither painful nor pruritic. He cannot remember any recent trauma to his foot. He has tried scratching the edge of the lesion, and some of the discolouration lifted off and has not recurred. He is a non-smoker, has minimal alcohol consumption and no significant medical history. He admits to spending lots of his youth in the sun. He has always used sunscreen but rarely applies it to the soles of his feet. Unfortunately, Frank's mother was recently diagnosed with a metastatic melanoma, and this is his primary concern. Dermoscopically, the border appears regular, with a uniform reddish-brown hue and an ordered parallel pattern.
The answer is C. Talon noir, also known as ‘black heel’ or calcaneal petechiae, is an asymptomatic benign condition caused by an accumulation of blood in the stratum corneum in the heel. It is caused by repeated trauma resulting in the rupture of fragile blood vessels, commonly seen in young adults who play sports, such as basketball or tennis. It has an equivalent version seen on the palms known as tache noire. The diagnosis is usually clinical, with the use of dermoscopy and paring of the lesions; biopsy is not required unless there is any ongoing diagnostic uncertainty or concern for melanoma. Morphologically these are grouped, punctate, linear, black/blue/dark red/brown macules with horizontally arranged petechiae.1 Melanocytic lesions and traumatic tattoo will not be entirely removed by paring. However, finding normal skin after removing the haemorrhagic material can serve as diagnostic confirmation.2 Left alone, these lesions will likely resolve spontaneously within six weeks but may recur if the traumatic aetiology is not avoided.
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