Re-evaluation of nailfold capillaroscopy in discriminating primary from secondary Raynaud's phenomenon and in predicting systemic sclerosis: a randomised observational prospective cohort study.

BACKGROUND: Primary Raynaud's phenomenon (pRP) is difficult to distinguish from secondary (sRP). Although nailfold capillaroscopy (NFC) may detect early alterations, no universal criteria yet discriminate between pRP from sRP. OBJECTIVES: To create and validate two NFC scores that could distinguish pRP from sRP and that could predict systemic sclerosis (SSc), respectively. METHODS: We performed NFC on two separate cohorts with isolated RP, and recorded number of capillaries per field, enlarged/giant capillaries, crossed/bizarre patterns, microhemorrhages, neoangiogenesis, rarefaction, edema, blood flow velocity, stasis. By multivariate regression analysis, we evaluated the adjusted prognostic role of these features in a derivation cohort of 656 patients. Results were used to construct algorithm-based prognostic scores (A and B). These scores were then tested on a confirmation cohort of 219 patients. RESULTS: Score A was unable to discriminate sRP from pRP (low negative predictive values with high positive predictive values for any cut-point); score B was unable to discriminate progression to SSc or a SSc-spectrum disorder (low positive predictive values with high negative predictive values for lower cut-points). CONCLUSION: NFC patterns, believed as specific, showed low discriminatory power and on their own are unable to reliably discriminate sRP from pRP or predict evolution to SSc.

Clinical characteristics of juvenile systemic sclerosis in Korea: 31-year single-center study.

Objective: To evaluate the clinical and laboratory characteristics, therapeutic drugs, and prognosis of juvenile systemic sclerosis (JSSc) at a single center in Korea. Methods: This study was a retrospective analysis of patients with JSSc aged <16 years at disease onset and who were treated at our hospital between January 1992 and April 2023. All patients met the Pediatric Rheumatology European Society/American College of Rheumatology/European League against Rheumatism provisional classification criteria for JSSc, and those with localized scleroderma (morphea) were excluded. Results: Among the 13 patients, proximal skin sclerosis (100%), Raynaud's phenomenon (RP) (84.6%), and sclerodactyly (69.2%) were present at the time of diagnosis. The most common symptom before diagnosis was RP, which was present in 10 patients (76.9%), whereas proximal skin sclerosis was observed in only five patients (38.5%). Thirteen patients had positive anti-nuclear antibody (ANA). At the time of diagnosis, five individuals had findings suggestive of interstitial lung disease (ILD) on a pulmonary function test (PFT) or chest computed tomography (CT), two of whom were asymptomatic. During follow-up, three patients developed ILD, one developed renal dysfunction, one developed heart disease, and none died. Conclusion: This study was the first descriptive analysis of clinical features of JSSc in South Korea. Clinical suspicion is essential for diagnosing JSSc in patients with RP, especially if ANA is positive; however, proximal skin sclerosis, which is crucial for diagnosing JSSc, was unrecognized in the early phase of the disease. PFT should be considered even if a patient is asymptomatic or has normal chest CT.

Raynaud's phenomenon in the feet of Arctic open-pit miners.

The literature on Raynaud's phenomenon (RP) in the feet is scarce, especially in the occupational setting. The primary aim of our study was to investigate the occurrence of RP in the feet of miners. As part of the MineHealth project, written surveys and clinical examinations were completed by 260 Arctic open-pit miners working in northern Sweden and Norway (participation rate 53.6%). Data on RP were collected using standardised colour charts and questionnaire items. Clinical examination included assessing the perception of vibration and pain in both feet. There were eight women and three men who reported RP in the feet. Four also had RP in their hands but none acknowledged any first-degree relatives with the condition. Nine reported exposure to foot-transmitted vibration and one to hand-arm vibration. Seven showed signs of neurosensory injury in the feet. To conclude, the occurrence of RP in the feet of miners was 4.4%. Most cases with RP in the feet did not report the condition in the hands and were exposed to vibration transmitted directly to the feet. There were no reports of a hereditary component. Most cases with RP in the feet also had clinical findings suggestive of peripheral neuropathy in the feet.

Neurosensory and vascular symptoms and clinical findings in the hands of Arctic open-pit miners in Sweden and Norway - a descriptive study.

This cross-sectional study aimed to describe exposure to cold climate and hand-arm vibration (HAV) as well as neurosensory and vascular symptoms and clinical findings among open-pit Arctic miners. It was based on data from questionnaires and physical examinations, including 177 men and 75 women from two open-pit mines in Sweden and Norway (response rate 54%). Working outdoors or in an unheated building or machine for at least two hours per day was reported by 44% and HAV exposure of the same duration by 10%. Neurosensory symptoms (e.g. reduced perception of touch) in the hands were reported by 47% and Raynaud's phenomenon by 14%. In brief conclusion, the study showed that Arctic miners were commonly exposed to both cold temperatures and HAV. They also reported a broad range of neurosensory and vascular symptoms in their hands and had abnormal clinical findings related to the symptoms. The results emphasise the need for additional preventive measures in this occupational setting.

Digital artery reconstruction with interposition vein graft: impact on secondary Raynaud's phenomenon.

OBJECTIVE: Patients with secondary Raynaud's phenomenon show a wide range of symptoms depending on the condition of vascular structures. If the symptoms are localized to specific fingers and angiography reveals a discrete segment of occlusion of a proper digital artery, we perform proper digital artery reconstruction with an interposition vein graft. The objective of this study was to evaluate the results of the surgery in patients with chronic hand ischemia. METHODS: A retrospective chart review was performed on patients who underwent proper digital artery reconstruction. Each digit that underwent grafting was analysed separately. The results of surgical intervention and recurrence based on patient symptoms were evaluated. Cox proportional hazards regression models were used to identify independent risk factors associated with recurrence, and the Kaplan-Meier method was used to predict the 5-year recurrence-free rate. RESULTS: A total of 79 digits from 57 patients were included in this study. The majority of patients demonstrated resolution of ischemic pain and ulceration (97.5% and 95.3%, respectively). Recurrence occurred in 16 (20.3%) patients during the follow-up period. In two cases (2.5%) surgery had no effect. In the multivariate Cox regression analysis, smoking and concomitant periarterial sympathectomy were significant factors associated with recurrence. In the Kaplan-Meier analysis, the 5-year recurrence-free rate in the total study population was 69.3%. CONCLUSIONS: Digital artery reconstruction using an interposition vein graft is an effective procedure for improving ischemic pain and ulceration in patients with Raynaud's phenomenon. Smoking and concomitant periarterial sympathectomy were significantly associated with recurrence.

Cold Hands or Feet: Is It Raynaud's or Not?

Raynaud's phenomenon is an exaggerated response to cold stimuli that may be primary or secondary. The diagnosis relies on patient history and physical examination to distinguish RP from other vasomotor dysfunction (e.g. acrocyanosis, pernio, small fiber neuropathy with vasomotor symptoms, and complex regional pain syndrome). Achenbach syndrome, or spontaneous venous hemorrhage, may also be mistaken for RP but is a self-limiting phenomenon. Laboratory evaluation and vascular diagnostic testing may identify SRP causes. Regardless of etiology, treatment includes warming with trigger avoidance, and consideration of vasodilators (eg. calcium channel, alpha-1 blockers). SRP with digital ulceration may require PDE5i, endothelin-1 receptor blockers, and prostanoids. Refractory cases may require pneumatic arterial pumps, botulinum toxin administration, or surgical sympathectomy.

Raynaud Phenomenon of the Nipple: A Clinical Case Report.

Objective: In Raynaud's phenomenon of the nipple there is a change in color, accompanied by pain or discomfort during breastfeeding. Case report: A 29-years old female patient, breastfeeding, develops a severe bilateral nipple pain during and after breastfeeding and biphasic change in nipple color, with difficulties in the breastfeeding technique. She was medicated with nifedipine and recommended application of warm compresses to the nipples and use of electric breast pump, showing complete resolution after four weeks of treatment. Conclusion: Raynaud's phenomenon of the nipple should be considered in breastfeeding women who report nipple pain or discomfort. In clinical practice, nipple pain is a very frequent complaint, and responsible for many cases of early abandonment of breastfeeding. It is therefore essential to make an early diagnosis and implement a correct and immediate treatment.

Esclerosis sistémica sine esclerodermia en una mujer con anticuerois antinucleares centroméricos, afectación pulmonar y digestiva: reporte de caso

Las entidadessineson poco comunes en reumatología. En la esclerosis sistémica progresiva, hay una variante de la forma cutánea limitada llamada esclerosis sistémicasineesclerodermia, cuya característica central es la falta de afectación cutánea, pero compromiso visceral presente. La positividad a los anticuerpos antitopoisomerasa o anticentromérico confirman el diagnóstico. El caso de este estudio es una mujer de 63 años con enfermedad intersticial pulmonar, afectación del tránsito intestinal y fenómeno de Raynaud, con ANA a títulos elevados con patrón centromérico y positividad para anticuerpos antitopoisomerasa. Ante un paciente con fenómeno de Raynaud, afectación visceral y ANA elevado, se le debe pedir anticuerpos específicos para diagnóstico de esclerosis sistémica en su variedadsine.

Sine entities are rare in rheumatology. In progressive systemic sclerosis there is a variant of the limited cutaneous form called systemic sclerosis sine scleroderma, whose central feature is the lack of skin involvement, but visceral involvement is present. Positive anti-topoisomerase or anti-centromere antibodies confirm the diagnosis. We present the case of a 63-year-old woman with interstitial lung disease, intestinal transit involvement and Raynaud's phenomenon, with high titers of ANA with a centromeric pattern and positivity for anti-topoisomerase antibodies. When faced with a patient with Raynaud's phenomenon, visceral involvement and elevated ANA, specific antibodies should be requested for the diagnosis of systemic sclerosis in its sine variety.

Efficacy of Radiofrequency Thermocoagulation of the Thoracic Sympathetic Nerve versus Chemical Excision in Pain Caused by Raynaud's Disease.

Objective: To investigate the effectiveness and safety of computed tomography (CT)-guided radiofrequency thermocoagulation (RFTC) of the thoracic sympathetic nerve versus chemical resection (CTS) for the treatment of pain caused by Raynaud's disease. Methods: Patients who underwent CTS or thoracic sympathetic nerve RFTC between March 2012 and March 2021 were enrolled in this retrospective study. There were 28 cases in the alcohol group (Group A) and 44 in the radiofrequency group (Group R). Visual analog scores (VAS) were collected from patients at different time points, as well as preoperative and postoperative finger end perfusion index (PI) and hand temperature (T). The efficiency, postoperative recurrence rate, complications, and improvement in postoperative quality of life were observed in both groups. Results: Pain scores at different follow-up times after surgery decreased in both groups compared to the preoperative period (P < 0.05). Postoperative T and PI were higher in both groups than preoperatively all (P < 0.05). The recurrence rate was higher in the R group than in the A group. Postoperative complications were observed in 13.6% and 25% of patients in groups R and A, respectively. Meanwhile, the postoperative quality of life improved in both groups, but the radiofrequency (RF) group was better than the alcohol group in terms of improvement in quality of life (P < 0.05). Conclusion: Both CT-guided CTS and RFTC of the thoracic sympathetic nerve provided good treatment outcomes. However, the RF group was superior to the alcohol group in terms of complication rate and quality of life improvement.

Real-world nailfold videocapillaroscopy in a referral centre in north-western Colombia: A real-life cohort

Introduction: Nailfold videocapillaroscopy is a non-invasive tool for the assessment of peripheral microcirculation, the main indication is the study of Raynaud's phenomenon, poorly standardized outside of this context. There is no clear information in real-life about the rea-sons for referral, the presence of clinical findings of autoimmune diseases, the frequency of patterns of autoantibodies, and specific capillaroscopic findings. Objective: The purpose of this survey is to describe the sociodemographic, clinical, paraclinical, and angioscopy findings of a cohort of subjects referred to a capillaroscopy service in North-western Colombia. Methods: A retrospective study was conducted, from 2015 to 2018. Categorical variables were expressed in frequency and percentage and quantitative variables in mean and standard deviation or median with interquartile range, depending on the distribution of the data. Results: A total of 318 capillaroscopies were performed for the first time. The main referral reason was Raynaud's phenomenon (n = 134; 42.1%). The most frequent baseline capillaroscopic pattern found was normal (n = 123; 38.7%). Of the 12 capillaroscopies that presented a non-specific pattern at a 6-month follow-up, only one (8.3%) progressed to a scleroderma pattern. In the subjects with systemic sclerosis, the most frequent clinical finding was sclerodactyly (n = 34; 37.8%), and 42/44 individuals (95.4%) had positive antinuclear antibodies; the most frequent pattern was centromere (n = 27; 64.3%) Conclusions: In a real-world setting, the main referral reason for capillaroscopy was Raynaud's phenomenon; more than a third of the subjects had normal capillaroscopic findings. Sclerodactyly was the most frequent clinical finding in patients with scleroderma capillaroscopic pattern.

Introducción: La videocapilaroscopia del lecho ungular es una herramienta no invasiva para la evaluación de la microcirculación periférica; la indicación principal es el estudio del fenómeno de Raynaud. Luego de una revisión de la literatura, no hay información clara sobre los motivos de remisión, presencia de hallazgos clínicos de enfermedades autoinmunes, frecuencia de patrones de autoanticuerpos y hallazgos capilaroscópicos específicos. Objetivo: Describir los hallazgos sociodemográficos, clínicos, paraclínicos y capilaroscópicos de sujetos remitidos a un servicio de capilaroscopia en el noroccidente colombiano. Métodos: Estudio retrospectivo de 2015 a 2018. Las variables categóricas se expresaron en frecuencias absolutas y porcentajes, y las variables cuantitativas en media y desviación estándar o mediana con rango intercuartílico, dependiendo de la distribución de los datos. Resultados: Se realizaron 318 capilaroscopias por primera vez. El principal motivo de remisión fue el fenómeno de Raynaud (n = 134; 42,1%). El patrón capilaroscópico basal más frecuente fue el normal (n = 123; 38,7%). De las 12 capilaroscopias que presentaron un patrón no específico en un seguimiento de seis meses, solo una (8,3%) progresó a un patrón de esclerodermia. En los sujetos con esclerosis sistémica, el hallazgo clínico más frecuente fue la esclerodactilia (n = 34; 37,8%), y 42/44 individuos (95,4%) tenían anticuerpos antinucleares positivos; el patrón más frecuente fue el centromérico (n = 27; 64,3%). Conclusiones: La razón principal de remisión para realizar una capilaroscopia fue el fenómeno de Raynaud; más de un tercio de los sujetos tenían hallazgos capilaroscópicos normales. La esclerodactilia fue el hallazgo clínico más frecuente en pacientes con patrón capilaroscópico de esclerodermia.

Worsening of Primary Raynaud's Phenomenon During Episodes of Pyrexia and Rigors in SARS-CoV-2 Infection.

Acute SARS-CoV-2 infection is associated with several cutaneous manifestations, including vasculitic digital ischemia. The reversal of digital ischemia in the primary Raynaud phenomenon (RP) arises from endothelial hypersensitivity to circulating adrenaline and noradrenaline and diminished vasodilatory innervation. SARS-CoV-2 can infect endothelial cells and be associated with raised adrenaline levels, reduced microvascular dilatory responses, and exaggerated clotting mechanisms. We report worsened RP in a patient with previously mild winter-time primary RP during the periods of fever and rigors from an acute SARS-CoV-2 infection contracted in a warm summer period. This reverted to the mild phenotype after recovery, and we discussed possible mechanisms for the brief exacerbation.

Cocaine-Induced Raynaud's Phenomenon: A Case Report.

We illustrate a notable case of a middle-aged male who presents to a community hospital with left third- and fourth-digit discoloration and pain for the past four days. On presentation to the emergency department, a urine drug screen was ordered which showed synthetic cannabinoids, cocaine, and amphetamines. Initial therapy of nitroglycerin paste, oral oxycodone, intravenous Dilaudid®, and aspirin was started, which resulted in decreased subjective pain. The pathophysiology and mechanism of cocaine-induced Raynaud's phenomenon (RP) are discussed. Our purpose in putting forward this case is to acknowledge cocaine use as a cause of secondary RP and to emphasize the importance of early recognition to reduce the occurrence of digital necrosis.

Part II: Cutaneous manifestations of peripheral vascular disease.

In this Part 2 of a 2-part continuing medical education series, we review the epidemiology of peripheral vascular disease, its association with cutaneous symptoms, and the diagnosis and evaluation of cutaneous features of vascular disorders. As peripheral vascular disease becomes more prevalent globally, it is essential for dermatologists to become competent at accurately recognizing and diagnosing cutaneous manifestations and directing individuals to receive appropriate care and treatment.

Analysis of Hand Function, Upper Limb Disability, and Its Relationship with Peripheral Vascular Alterations in Raynaud's Phenomenon.

This study aimed to compare vascular involvement, hand functionality, and upper limb disability between Raynaud's phenomenon participants and controls. Also, we analyzed the relationships between vascular impairment, mobility, and strength with disability in this Raynaud population. We conducted a case-control study with fifty-seven participants. We registered sociodemographic and clinical data; vascular variables (temperature, cold test, blood flow, and oxygen saturation); functional variables (pinch strength, range of motion), and disability (Shortened Disabilities of the Arm, Shoulder and Hand Questionnaire) (Q-DASH). Raynaud participants present more disability in all Q-DASH subscales, lower hands' temperature pre and post cold test, decreased blood flow on radial artery, decreased ranges of motions at passive extension of index finger, and active flexion and extension of thumb than the healthy controls. The multivariate regression analysis showed that extension of the index finger, lateral pinch strength, and oxygen saturation were significantly associated with disability in RP, almost the 55% of the total variance on the upper limb, 27% at sports/arts, and 42% at work. Our findings suggest that RP has a disabling effect on the upper extremities and a practice of activities in people who suffer it. Also, disability in Raynaud seems to be more related with hand mobility and strength impairment than vascular injury.

Technetium-99m hand perfusion scintigraphy (Raynaud's scan) as a method of verification in hand arm vibration syndrome: a review.

It is important to assess the blood flow of fingers in the verification of hand-arm vibration syndrome. In the Republic of Korea, most assessments of the blood flow in the fingers are performed using a cold provocation test with finger skin color change. However, this test is a non-objective method with a relatively low sensitivity, leading to possible social and legal problems. Thus, we reviewed the characteristics of several tests that assess the blood flow in the fingers. Among these tests, using the radioactive isotope method, Raynaud's scan has a relatively higher sensitivity and specificity than other tests, provides objective results, and is approachable in many hospitals. So we suggest using Raynaud's scan as an alternative test when cold provocation test with finger skin color change is negative in vibration exposed worker.

Simpatectomía de la arteria radial y ulnar en contexto de úlcera digital secundaria a esclerosis sistémica cutánea localizada / Radial and ulnar artery sympathectomy in the context of digital ulcer secondary to localized cutaneous systemic sclerosis

SPeripheral sympathectomy is a procedure which has shown high rates of decreasing ischemic pain, recover functionality and wound healing, preventing the progression of the disease and further complications. We present a female patient with severe Raynaud´s phenomenon secondary to localized cutaneous systemic sclerosis complicated who presented digital ulcer treated with a sympathectomy of the radial and ulnar artery at the wrist level, undergoing post-operative follow-up.

[Functional vascular acrosyndromes]. / Funktionelle akrale Durchblutungsstörungen.

Vascular acrosyndromes are characterized by sparse, uniform clinical manifestations and a variety of possible pathomechanisms. The present article focuses on the functional entities. Raynaud phenomenon is based on cold- or stress-induced vasospasms of acral arteries. It is defined by the color changes of the skin, in the typical case white-blue-red (tricolore). The long fingers are most commonly affected. The etiology is unknown, and the pathophysiology is poorly understood. A distinction is made between primary and a secondary Raynaud phenomenon. The most important underlying diseases include collagenosis, primarily systemic sclerosis, and malignancies; furthermore, medications and drugs may promote vasospasm. Treatment is aimed at preventing or breaking the vasospasm, but has been only partially effective in doing so. Acrocyanosis is a vasospastic dystonic acral disorder that results in permanent reddish-livid discoloration, especially of the hands and feet. Secondary forms occur in collagenosis, malignancies, and myelodysplastic syndromes. The etiology and pathophysiology are virtually unknown. Targeted pharmacological intervention is not possible. Unlike all other vascular acrosyndromes, erythromelalgia is characterized by hyperemia. The primary form is a genetic sodium channelopathy, while secondary forms include malignancies, connective tissue diseases, and myelodysplastic syndromes. The symptoms are often distressing and disabling. Therapy requires a multimodal approach that includes both nonpharmacological and pharmacological strategies. Close interdisciplinary collaboration is essential for the management of this disease.

Incidence, remission, and persistence of Raynaud's phenomenon in the general population of northern Sweden: a prospective study.

BACKGROUND: Raynaud's phenomenon is common condition, but little is known about the natural course. The primary aim of this study was to determine the incidence, remission, and persistence proportions of Raynaud's phenomenon in the general population of northern Sweden. Secondary aims were to determine how individual and exposure factors affect the course of Raynaud's phenomenon, and to assess gender differences. METHODS: A prospective, survey-based, closed-cohort study was conducted on a sample of men and women between 18-70 years of age, living in northern Sweden. Data on Raynaud's phenomenon characteristics and general health status were collected during the winters of 2015 (baseline) and 2021 (follow-up). Rates of incidence, remission, and persistence were calculated. Binary logistic regression was used to determine the association between baseline variables and the course of Raynaud's phenomenon. RESULTS: The study population consisted of 2703 women (53.9%) and 2314 men. There were 390 women (14.5%) and 290 men (12.7%) reporting Raynaud's phenomenon in the follow-up survey. The annual incidence proportion was 0.7% among women and 0.9% among men (gender difference p = 0.04). The annual remission proportion was 4.4% and 5.5%, respectively (p = 0.05). Having sustained a cold injury affecting the hands since baseline was significantly associated with incident Raynaud's phenomenon (OR 3.92; 95% CI 2.60-5.90), after adjusting for age and gender. CONCLUSIONS: In the general population of northern Sweden, Raynaud's phenomenon is a common but variable condition, where symptoms may remit over time. Men had a higher incidence proportion than women. The results support a possible causal pathway where cold injury can precede the onset of Raynaud's phenomenon.

The impact of Raynaud's phenomenon on work ability - a longitudinal study.

OBJECTIVE: To determine if having Raynaud's phenomenon (RP) affects the work ability, job retainment, or occurrence of sick leave. METHODS: Surveys on the working-age general population of northern Sweden were conducted in 2015 and 2021, gathering data on RP, occupation and sick leave. Work ability was assessed using the Work Ability Score. RESULTS: The study population consisted of 2,703 women and 2,314 men, among which 390 women and 290 men reported RP at follow-up. For women, the mean [standard deviation (SD)] Work Ability Score was 8.02 (2.24) for subjects reporting RP and 7.68 (2.46) for those without RP. For men, the corresponding numbers were 7.37 (2.03) and 7.61 (2.14), respectively. Multiple linear regression did not show an association between RP status and work ability (p = 0.459 for women and p = 0.254 for men), after adjusting for age, body mass index, physical workload, cardiovascular disease, and perceived stress. Having retained the same main livelihood since baseline was reported by 227 (58.5%) women with RP, 1,163 (51.2%) women without RP, 152 (52.6%) men with RP, and 1,075 (54.1%) men without RP (p = 0.002 for women and p = 0.127 for men). At follow-up, any occurrence of sick leave during the last year was reported by 80 (21.4%) women with RP, 410 (18.6%) women without RP, 48 (17.1%) men with RP, and 268 (13.7%) men without RP (p = 0.208 for women and p = 0.133 for men). Among those reporting sick leave, the mean (SD) duration in months was 2.93 (3.76) for women with RP, 3.00 (4.64) for women without RP, 2.77 (3.79) for men with RP, and 2.91 (12.45) for men without RP (p = 0.849 for women and p = 0.367 for men). CONCLUSION: For neither women nor men was there a significant effect of having RP on work ability. Women with RP reported a slightly higher job retainment compared to those without the condition, while there was no difference in job retainment among men. For neither gender did the presence of RP influence the occurrence of recent sick leave, nor did it affect the length of time away from work.

Is there any Sympathetic Skin Response Abnormality in Raynaud Phenomenon?

Objectives: This study aimed to evaluate sympathetic skin response (SSR) among patients with Raynaud phenomenon (RP). SSR is a technique for assessment of the damage of peripheral neuropathies and the disorders of the sympathetic system. Methods: Between January 2015 and December 2018, approximately 20 patients with RP and 20 healthy subjects (control group) were recruited from patients referred to the outpatient clinics of Shiraz University of Medical Sciences, Shiraz, Iran. All participants were clinically examined and the SSR was evaluated using a standard protocol. SSR is abnormal when the latency is prolonged and/or the amplitude is reduced. Results: The RP group consisted of 19 women (95%) and one male (5%); three patients (15%) had primary Raynaud's phenomenon (PRP) and 17 patients (85%) had secondary Raynaud's phenomenon. The control group consisted of 16 women (80%) and four males (20%). The mean age of the RP group and control subjects was 43.1 ± 9 and 36.7 ± 8.6 years, respectively. The SSR to the electrical stimulus was absent in three patients with PRP. The total median nerve mean latencies in the upper limb were 1.90 ± 0.57 and 1.19 ± 0.52 seconds for the RP group and control groups, respectively (P <0.001). These findings revealed significantly prolonged SSR latencies in the RP group, while the mean amplitude showed no significant differences in both groups (P = 0.756). Conclusion: Absence or prolonged latency of SSR was associated with the disorders of the unmyelinated axons in the sympathetic system. The findings of the present study suggested the disorders of unmyelinated axons in Raynaud's phenomenon.