Ok so my issue has been going on for about a year now.
I have these little red circles on my wrist and they disappear then migrate to another place on my body, sometimes my inner elbow crease and sometimes my inner thighs (generally where it is warmer to breed I guess) but that doesn't explain why they always appear on my wrists.

The doctors thought it was ring worm as they are red circles and itchy and to me also looked like them.

They start small and a bit of an itch and then they get bigger and spread to other areas - only one circle at a time which eventually goes than reappears in another place on my arm.

Sometimes I can go a few weeks/months without them and I sigh relief and then they come back again.

The doctors have given me a few creams including Daktacort Hydrocortisone and Terbinafine Hydrochloride but although they feel nice going on, it doesn't get rid of the rash.
I have tried allergy tablets to stop the itching but this also doesn't work.

Sometimes the circles are semi circles - like horse shoe type shapes and inflammed and red - slightly raised rings.

2 weeks ago I had one on my inner elbow which has now gone, but now reappeared on my left wrist and its driving me crazy.
Tonight I noticed it's now got white in the middle of the raised red bit after I itch it.

See pictures attached of before and after itching it. http://imgur.com/a/DWpau

Any ideas welcome! My doctors don't have a clue - they thought it might be diabetes related (I am insulin diabetic but in very good control)