I had a clue what the diagnosis might be when I was asked if I could “squeeze in Sally Smith for leg numbness and a groin rash”, although I didn’t know the extent of the numbness or the specifics of the rash.

So we double-booked her and I listened to her story. The numbness was only in the front of her left thigh and started somewhere around the groin. Her strength was normal and the sensation below the knee was perfectly normal.

When I touched the numb area she told me it hurt, so it wasn’t just numb — it was numb and painful at the same time.

Looking at the rash, it was a cluster of blisters in her left groin about the size of my fist, and she also had a small patch of smaller blisters around the corner in the upper left gluteal area.