Answer to question (EMQ) of the day – a history of weakness and fatigue

Thanks for all of your great responses to our question of the day – some good analyses and discussion.

So here we go with the likely pathology …

• Symmetrical findings make a central lesion less likely (they would localise).
• The reflexes and sensation are intact, making a cord or peripheral nerve lesion unlikely.
• The absence of fatigability makes a neuromuscular junction lesion less likely (myasthenia etc).
• This sounds like a myopathy: the rash therefore suggests polymyositis (the rash is a heliotropic rash named after the purple heliotrope flower). The CK is likely to be very high (in the thousands, NR <150 iu/l).
• The dysuria and cough are intended as distracters.

Look out for our next question of the day coming soon, and remember there are thousands more in the login area!