What Causes Itchiness And Swelling Of Fingers?

Hi,I am having finger swelling this week. I experienced it for several times in the day and it starts with a feeling like tangling or itching feeeling. Later it results in swollen fingers. Swelling goes away itsefl in about an hour. It generally happens to my right hand fingers but it happened to left hand fingers as well. I experienced it for all my right hand fingers in different times. I generally have it after i wash my hands with cold water. However, not all cold water wash does it. I also had it due to cold outside and ones after i touched my cold keys. My blood work showed normal white blood cell values and esr showed 17 while the normal range was given as 0-15. Hemoglobin test came negative for diabetes. What can be the cause behind this temperory but frequent finger swelling? Thanks,