**2. Diagnosis of Raynaud's phenomenon**

The diagnosis of RP is clinical and is based on direct observation of the vasospastic attacks [1]. Photographs that document the vasospastic attacks could also be used to confirm the history [2]. In routine clinical practice, it is not necessary to perform a cold provocation test to make a definite diagnosis of RP [1].

Observation of at least biphasic color changes is necessary for the diagnosis, as pallor and cyanosis are considered to be the most important signs. In a recent international consensus for the diagnosis of RP (Maverakis et al. [3]), a three-step approach for the diagnosis of RP has been suggested. The first two steps include asking more general questions: (I) a question about unusual sensitivity of the fingers to cold and (II) a question about "occurrence of biphasic color changes during the vasospastic episodes (white and blue)." Finally, during step III, the physician calculates the disease score by asking seven questions to the patient ((1) episodes are triggered by factors other than cold, i.e., emotional stress; (2) episodes involve both hands even if they are asynchronous or asymmetric; (3) numbness and paresthesias accompany vasospastic attacks; (4) well-demarcated border between the affected and unaffected skin; (5) photographs provided by the patient; (6) vasospastic episodes that affect other body parts such as the nose, ears, feet, and areolas; (7) occurrence of triphasic color changes during vasospastic attacks, e.g., white, blue, and red). If the score from step III is ≥3, the patient is diagnosed with RP [3].
