First point is I'm not that concerned about it! It's not menigitis.
DS2 is 10 and prone to eczema, so when she showed me an apparent new patch just below his navel last week, I assumed that's what it was. It's small area, maybe 10cm across consisting of discrete, bright red, well circumscribed flat 'spots', each maybe 7-8 mm across, and topped with a scab. They're a bit itchy.
Hydrocortisone cream didn't touch them.
Then, a week later (yesterday) I was looking at them and I see that where in places the scabs have fallen off, they've left a pit! The red 'spot' as in red patch on his skin is still there, but with a clean pit, 2mm across in the centre of each!
What could it be?