What’s already known about this topic?
Raynaud’s phenomenon (RP) is a reversible vasospastic disorder that may be provoked by cold or emotional stress. This phenomenon can be occur without underlying disease or unknown etiology which named as primary RP (pRP). The essential finding of pRP is aggravation of symptoms by exposure cold and the detection of color changes (turn white, blue, or both). The diagnosis is clarified after exclusion of possible underlying diseases with checking nail capillaroscopy and laboratory panel such as complete blood counting, inflammatory parameters, metabolic panel, antibodies, enzymes etc. However, any specific laboratory marker was not determined for diagnosing pRP. Therefore, researchers tried to determine an objective laboratory marker that is highly specific and scientific for pRP.