Tops Of Toes Turned Purple, Itching. What Could It Be?

I am a 72 year old woman and my symptoms, like many above, started about three years ago....color hot pink turning to purple after about a week; affecting one or more toes at a time;episodes last approx 2 wks, occurring several months apart, any time of the year (first time was in the summer);tops of toes only, never underneath or between; usually over joint closest to nail but not confined to joint area alone; itching occurs always in evening/night especially when toes are warm (walking barefoot on cool floor eases itch); wear Burkinstock sandles, so open to air and light. Don t think it is Chilblains but would love to find out what else it could be.