Matt, a 41-year-old electrician, presents with intermittent right arm swelling for about one month, worsening over the past few days and now with associated purple-red discolouration and pain in the hand.

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<p>Matt, a 41-year-old electrician, presents with intermittent right arm swelling for about one month, worsening over the past few days and now with associated purple-red discolouration and pain in the hand.</p><p>There has been no associated injury, trauma, fever or systemic features. Matt is generally well, has no history of note and takes no medications. He is right handed and does a lot of work with his arms raised overhead.</p><p>On examination, vital signs are within normal range and the radial artery pulse is palpable.</p><p>The right hand is swollen and discoloured compared with the left, and the superficial veins of the right shoulder are dilated (pictured). Examination is otherwise unremarkable.</p>

Dr Kate Kelso is a GP and medical editor at Australian Doctor.