I experience this in one of my fingers, I dont know of any treatment but I want you to know that you are not alone, if it is a little cold in a room or outside, my fingers and toes are blue and my index finger on my right hand HURTS! but once i warm it up it goes away for the most part. My doctor says that your fingers turning blue is apart of haveing Lupus.

Arthritis is very common in people with lupus. There may be pain, with or without swelling. Stiffness and pain may be particularly evident in the morning. Arthritis may be a problem for only a few days or weeks. Because lupus is a condition that can change over time and is not always predictable, it is a good idea to keep a record of your symptoms, which parts of your body are affected and any situations or activities that seem to trigger your symptoms. Remember to include any diet changes, activities and stress changes this will help predict the things that cause flare ups and provide valuable information for your doctor's treatment.
You may want to try a cool (not cold) compress to ease the pain and stretching and exercise your hands and fingers to increase the blood flow to your finger tips.