**3. Classification of Raynaud's phenomenon**

RP is classified into two categories, i.e., primary and RP [1, 4, 5, 6].

Primary RP is an isolated finding in the absence of an underlying pathology, while secondary RP is a syndrome in the context of another disease. The patients with primary RP have a younger age of onset (below 30 years), sparing of the thumb, and benign course without the development of digital ulcers [4, 6, 7].

On the contrary, secondary RP is characterized with later age of onset above 30 years, thumb involvement, and a more severe course with possible development of trophic changes in some cases (digital ulcerations, digital necrosis) [4, 6, 7]. In these cases, a focused, complaint directed history and physical examination aim to reveal clinical symptoms and findings that confirm the presence of an underlying disease, e.g., connective tissue disease (CTD) or other disorders. The secondary RP is a characteristic feature in a number of rheumatic diseases. In systemic sclerosis (SSc)/scleroderma, it is with the highest frequency of approximately 95% [8]. RP could also be a sign in a spectrum of nonrheumatic pathology that also should be recognized and properly differentiated by the rheumatologists in routine clinical practice (**Table 1**) [8–14].

cold and emotional stress [1]. Other acral parts, e.g., the nose, lips, and ears, may be also affected. It manifests usually in three phases, ischemia, asphyxia, and reactive hyperemia, during which skin color changes occur consecutively from white to blue and red. A character-

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

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

Primary RP is an isolated finding in the absence of an underlying pathology, while secondary RP is a syndrome in the context of another disease. The patients with primary RP have a younger age of onset (below 30 years), sparing of the thumb, and benign course without the

On the contrary, secondary RP is characterized with later age of onset above 30 years, thumb involvement, and a more severe course with possible development of trophic changes in some cases (digital ulcerations, digital necrosis) [4, 6, 7]. In these cases, a focused, complaint directed history and physical examination aim to reveal clinical symptoms and findings that confirm the presence of an underlying disease, e.g., connective tissue disease (CTD) or other disorders. The secondary RP is a characteristic feature in a number of rheumatic diseases. In systemic

istic feature of RP is the clear demarcation between the affected and unaffected area.

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

**3. Classification of Raynaud's phenomenon**

development of digital ulcers [4, 6, 7].

RP is classified into two categories, i.e., primary and RP [1, 4, 5, 6].

definite diagnosis of RP [1].

28 Newest Updates in Rheumatology

diagnosed with RP [3].

Together with clinical examination, laboratory, immunological, and capillaroscopic assessments facilitate the internal differential diagnosis of secondary RP and reveal the definite final diagnosis.

*Nailfold capillaroscopy* is a noninvasive, easy-to-perform method for diagnosis and differential diagnosis of patients with primary and secondary RP in rheumatic diseases (particularly the scleroderma-spectrum disorders), which is of crucial importance because of the different severity, prognosis, and therapeutic approach. Normal capillaroscopic pattern is an established diagnostic criterion for the diagnosis of primary RP. In addition, it has been found that capillaroscopic pattern in healthy individuals is constant for long periods of time. During the follow-up of patients with RP, it has been found that the appearance of abnormal capillaroscopic findings inherits a positive predictive value of 47% for the development of CTD that is higher as compared with the predictive value of the positive antinuclear autoantibody (ANA) test (30%) [15]. The appearance of giant capillaries is the earliest capillaroscopic sign of microangiopathy and represents a local response to tissue hypoxia. In RP patients, nailfold capillaroscopic analysis should be performed every 6 months and more often if new alarming symptoms appear. The capillaroscopic examination should be performed in all patients with symptoms of RP even in those cases without clinical and laboratory signs of systemic rheumatic disease, because the abnormal capillaroscopic picture inherits a high positive predictive value for the development of CTD.


**Table 1.** Differential diagnosis of secondary Raynaud's phenomenon in rheumatologic practice.
