Sorry for the bandwidth silence - life got a little bit hectic
Three days in hospital - surgery and then another week and a half off work to recover.
It was an abscess - it formed incredibly suddenly and doubled in size during my first day at the hospital so emergency surgery was required
I'm doing much better now and looking forward to getting back to the laundry renovations in a week or two (on the last stage now - just need to install a bench and put all the cupboards together [*cough* flatpack *cough*] and I'm done)