Thermographic parameters in the diagnosis of secondary Raynaud's phenomenon

Infrared Thermography as a Method of Verification in Raynaud's Phenomenon

Raynaud's phenomenon (RP) is characterized by the episodic whitening of the fingers upon exposure to cold. A recently described thermographic algorithm was proposed as a diagnostic replacement of the currently applied finger systolic pressure (FSP) test. The aim of the study was to evaluate the performance of the thermographic algorithm when applied in patients suspected of having RP. Forty-three patients were examined using thermographic imaging after local cooling of the hands in water of 10 °C for 1 min. The thermographic algorithm was applied to predict the probability of RP. The performance of the algorithm was evaluated with different cut-off levels. A new algorithm was proposed based on patients from the target population. The performance of the tested algorithm was noninferior to the FSP test, when a cut-off level of 0.05 was applied, yielding a sensitivity and specificity of 69% and 58%, respectively. The accuracy was 66%. The FSP test had a sensitivity and specificity of 77% and 37%, respectively, and the accuracy was 59%. The thermographic method proved useful for detecting RP and was able to replace the FSP test as a diagnostic test. The alternative algorithm revealed that other thermographic variables were more predictive of the target population, but this should be verified in future patients.

Characteristic Features of Infrared Thermographic Imaging in Primary Raynaud's Phenomenon

Raynaud’s phenomenon (RP) is characterized by the episodic whitening of the fingers upon exposure to cold. Verification of the condition is crucial in vibration-exposed patients. The current verification method is outdated, but thermographic imaging seems promising as a diagnostic replacement. By investigating patients diagnosed with RP, the study aimed at developing a simple thermographic procedure that could be applied to future patients where verification of the diagnosis is needed. Twenty-two patients with primary RP and 58 healthy controls were examined using thermographic imaging after local cooling of the hands for 1 min in water of 10°C. A logistic regression model was fitted with the temperature curve characteristics to convey a predicted probability of having RP. The characteristics time to end temperature and baseline temperature were the most appropriate predictors of RP among those examined (p = 0.004 and p = 0.04, respectively). The area under the curve was 0.91. The cut-off level 0.46 yielded a sensitivity and specificity of 82% and 86%, respectively. The positive and negative predictive values were 69% and 93%, respectively. This newly developed thermographic method was able to distinguish between patients with RP and healthy controls and was easy to operate. Thus, the method showed great promise as a method for verification of RP in future patients. Trial registration: ClinicalTrials.gov NCT03094910.

New perspectives in the imaging of Raynaud's phenomenon

The last 10-20 years have seen huge strides in imaging science. The aim of this review article is to share with the reader the key recent advances in non-invasive imaging of the digital (finger) vasculature in patients with Raynaud's phenomenon (RP), including in systemic sclerosis (SSc)-related digital vasculopathy. For the rheumatologist, seeing a patient with RP is an opportunity for early diagnosis of an underlying SSc-spectrum disorder or (conversely) for reassuring the patient with primary (idiopathic) RP. Non-invasive imaging techniques can help to provide diagnostic certainty. In addition, they can provide new insights into pathophysiology and have the potential to facilitate the development of much needed effective treatments by providing primary and secondary endpoints for randomized controlled trials: validation studies are ongoing. This review article focuses on nailfold capillaroscopy, thermography, and laser Doppler methods but also discusses (briefly) other technologies, including optical coherence tomography, multispectral imaging, and photoacoustic imaging. Key recent advances are the increasing use/availability of nailfold capillaroscopy (and better understanding of the role of low-cost hand-held devices), increased accessibility of thermography (including mobile phone thermography), and increased application of laser Doppler methods to the study of RP/digital vasculopathy (in particular of laser Doppler imaging and laser speckle contrast imaging, both of which measure blood flow over an area rather than at a single site). In an era of precision medicine, non-invasive imaging techniques can help stratify risk of (a) SSc in the patient with RP and (b) digital vascular disease progression in the patient with an SSc-spectrum disorder.

Infrared thermography in children: a reliable tool for differential diagnosis of peripheral microvascular dysfunction and Raynaud's phenomenon?

BACKGROUND

Infrared Thermography (IRT) has been used for over 30 years in the assessment of Raynaud Phenomenon (RP) and other peripheral microvascular dysfunctions in adults but, to date, very little experience is available on its use in children for this purpose. The first aim of the study was to assess reproducibility of thermographic examination after cold exposure by comparing inter-observer agreement in thermal imaging interpretation. The secondary aim was to evaluate whether IRT is reliable to diagnose and differentiate peripheral circulation disturbances in children.

METHODS

Children with clinical diagnosis of primary Raynaud's phenomenon (PRP), secondary RP (SRP), acrocyanosis (AC) and age-matched controls underwent sequential measurements of skin temperature at distal interphalangeal (DIP) and metacarpophalangeal (MCP) joints with IRT at baseline and for 10 min after cold challenge test. Intraclass correlation coefficient (ICC) was calculated for inter-rater reliability in IRT interpretation, then temperature variations at MCP and DIP joints and the distal-dorsal difference (DDD) were analysed.

RESULTS

Fourteen PRP, 16 SRP, 14 AC and 15 controls entered the study. ICC showed excellent agreement (> 0.93) for DIPs and MCPs in 192 measures for each subject. Patients with PRP, SRP and acrocyanosis showed significantly slower recovery at MCPs (p < 0.05) and at DIPs (p < 0.001) than controls. At baseline, higher temperature at DIPs and lower at MCPs was observed in PRP compared with SRP with significantly lower DDD (p < 0.001). Differently from AC, both PRP and SRP showed gain of temperature at DIPs and less at MCPs after cold challenge. PRP but not SRP patients returned to DIPs basal temperature by the end of re-warming time. Analysis of DDD confirmed that controls and PRP, SRP and AC patients significantly differed in fingers recovery pattern (p < 0.05).

CONCLUSION

IRT appears reliable and reproducible in identifying children with peripheral microvascular disturbances. Our results show that IRT examination pointed out that PRP, SRP and AC patients present significant differences in basal extremities temperature and in re-warming pattern after cold challenge therefore IRT can be suggested as an objective tool for diagnosis and monitoring of disease.

Relation between finger cold-induced vasodilation and rewarming speed after cold exposure

Purpose

The risk for local cold injuries has been linked to poor cold-induced vasodilation (CIVD) during cold exposure and to poor rewarming after cold exposure. The purpose of this study is to establish the relation between CIVD and rewarming speed.

Methods

Twelve participants immersed one hand in ice water for 30 min to evoke CIVD and the other hand in ice water for 10 min to investigate the rewarming profile. The ring, middle and index fingertip temperatures were monitored during hand immersion and the resistance index of frostbite (RIF) was calculated. RIF depends on minimal (T_min) and mean (T_mean) finger skin temperature and onset time. Rewarming was quantified using an infrared imaging system and the rewarming speed over 19 min was determined.

Results

T_min (5.8 ± 3.0 °C) and T_mean (10.4 ± 3.0 °C) caused non-distinctive contributions to the total RIF-scores so that onset time (12.7 ± 3.1 min) became the dominant factor. A significant negative correlation between RIF and rewarming speed was found (r_s = − 0.60, p = 0.041).

Conclusions

The negative relation between RIF and rewarming speed may be explained by the common observation that onset time relates to the temperature of fingertip tissue, while T_min, T_mean and rewarming speed relates to body thermal status. The rewarming test is to be preferred over the CIVD test in terms of ease of use, but the predictive value of the rewarming test for cold injuries is limited, cannot replace the RIF since onset time of finger vasodilation is not included and should be further investigated.

The efficacy and safety of Danggui-Sayuk-Ga-Osuyu-Saenggang-tang on Korean patients with cold hypersensitivity in the hands: study protocol for a pilot, double-blind, randomized, placebo-controlled, parallel-group clinical trial

Background

In recent years, cold hypersensitivity in the hands (CHH) has become a common ailment of women in Korea. It can lead to gynecological problems such as irregular menstruation, miscarriage, and infertility. Traditionally, Korean herbal medicine has been the primary treatment method used to balance thermoregulation in the human body; however, its effectiveness has not been confirmed through systematic study. Thus, in this trial, we will investigate the feasibility of a full randomized clinical trial, Danggui-Sayuk-Ga-Osuyu-Saenggang-tang (DSGOST) in Korean women with CHH.

Methods

This study will be a pilot, multicenter, double-blind, randomized, parallel-group, two-arm, placebo-controlled clinical trial. A total of 66 participants will be randomly divided into two groups, a DSGOST treatment group and a placebo control group, in a 1:1 ratio using a web-based randomization system. Each group will take DSGOST or placebo three times daily for 6 weeks. The primary outcome will be measured using Visual Analogue Scale (VAS) scores of CHH. Secondary outcomes will include changes in skin temperature of the hands, Clinical Global Impressions (CGI) scale scores, recovery rate of skin temperature of the hands after the cold stress test, and the Korean version of the WHO Quality of Life Scale, abbreviated version (WHOQOL-BREF).

Discussion

This trial will be the first trial to reflect the newly defined disease range of CHH which was compiled by Korean medicine expert consensus. This study will provide considerable evidence for further large-scale trials and general clinical guidelines for CHH in the Korean medical field.

Trial registration

This study is registered at ClinicalTrials.gov, ID: NCT02645916. Registered on 30 December 2015.

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2002-8) contains supplementary material, which is available to authorized users.

International consensus criteria for the diagnosis of Raynaud's phenomenon

Vasoconstriction accompanied by changes in skin color is a normal physiologic response to cold. The distinction between this normal physiology and Raynaud's phenomenon (RP) has yet to be well characterized. In anticipation of the 9th International Congress on Autoimmunity, a panel of 12 RP experts from 9 different institutes and four different countries were assembled for a Delphi exercise to establish new diagnostic criteria for RP. Relevant investigators with highly cited manuscripts in Raynaud's-related research were identified using the Web of Science and invited to participate. Surveys at each stage were administered to participants via the on-line SurveyMonkey software tool. The participants evaluated the level of appropriateness of statements using a scale of 1 (extremely inappropriate) through 9 (extremely appropriate). In the second stage, panel participants were asked to rank rewritten items from the first round that were scored as "uncertain" for the diagnosis of RP, items with significant disagreement (Disagreement Index > 1), and new items suggested by the panel. Results were analyzed using the Interpercentile Range Adjusted for Symmetry (IPRAS) method. A 3-Step Approach to diagnose RP was then developed using items the panelists "agreed" were "appropriate" diagnostic criteria. In the final stage, the panel was presented with the newly developed diagnostic criteria and asked to rate them against previous models. Following the first two iterations of the Delphi exercise, the panel of 12 experts agreed that 36 of the items were "appropriate", 12 items had "uncertain" appropriateness, and 13 items were "inappropriate" to use in the diagnostic criteria of RP. Using an expert committee, we developed a 3-Step Approach for the diagnosis of RP and 5 additional criteria for the diagnosis of primary RP. The committee came to an agreement that the proposed criteria were "appropriate and accurate" for use by physicians to diagnose patients with RP.

Effect of Korean red ginseng on cold hypersensitivity in the hands and feet: study protocol for a randomized controlled trial

Background

Cold hypersensitivity in the hands and feet (CHHF) is one of the most common complaints among Asians, especially in women. Korean red ginseng (KRG), which is a steamed form of Panax ginseng, has vasodilating action in the peripheral vessels and increases blood flow under cold stress. However, few studies have evaluated the effect of KRG on cold hypersensitivity.

Methods/Design

This trial is a randomized, double-blind, placebo-controlled trial in 80 CHHF patients. The trial will be implemented at Kyung Hee University Hospital at Gangdong in Seoul, Korea. The participants will take KRG or a placebo for eight weeks, after which they will be followed-up for four weeks. During the administration period, six capsules of 500 mg KRG or placebo will be provided twice a day. The primary outcome is change of skin temperature in the hands between baseline and after treatment. The secondary outcomes include the visual analogue scale scores of cold hypersensitivity in the hands, change of skin temperature and the VAS scores of cold hypersensitivity in the feet, the recovery rate of the skin temperature by the cold stress test of the hands, the distal-dorsal difference of the hands, power variables of heart rate variability, and the 36-item short form health survey.

Discussion

This study is the first trial to evaluate the efficacy of KRG on CHHF by using infrared thermography. Our study will provide basic evidence regarding CHHF.

Trial registration

CliniacalTrials.gov NCT01664156

Influence of the cold challenge on the discriminatory capacity of the digital distal-dorsal difference in the thermographic assessment of Raynaud's phenomenon

OBJECTIVES

To investigate the influence of a standardised cold stress test (CST) on the thermographic 'distal-dorsal difference' (DDD) and its capacity to differentiate between disease states in the assessment of Raynaud's phenomenon (RP), and to compare the discriminatory capacity of the DDD of individual digits with composite indices of multiple digits.

METHODS

Thermographic images of 55 patients with primary RP (PRP, n=27) and systemic sclerosis (SSc, n=28) who had undergone assessment of RP were retrospectively reviewed. The DDD for individual digits, and composite scores of multiple digits, were calculated at baseline (23°C), and at 10 min following CST. The discriminatory capacity of the mean DDD, and the proportion of patients with a clinically meaningful DDD of <-1°C, were assessed for individual digits and composite indices, at baseline and following cold challenge.

RESULTS

There was a more pronounced decrease of the DDD (indicating reduced distal perfusion) following CST in patients with PRP compared to SSc. The disparity in response to CST between groups narrowed the differences that were present at baseline, reducing the discriminatory capacity of the DDD for all endpoints. Sparing of the thumbs occurs to a greater extent in SSc (P<0.005) compared with PRP (P<0.05) but does not facilitate differentiation between groups. Large variability of the DDD within groups precludes easy differentiation between disease states. Composite indices of multiple digits are preferable to individual digital assessment.

CONCLUSIONS

The discriminatory capacity of the DDD is lost following CST. The CST may not be essential in the thermographic assessment of RP, potentially allowing greater use of thermography in clinical practise.

Core cooling and thermal responses during whole-head, facial, and dorsal immersion in 17 °C water

This study isolated the effects of dorsal, facial, and whole-head immersion in 17 °C water on peripheral vasoconstriction and the rate of body core cooling. Seven male subjects were studied in thermoneutral air (∼28 °C). On 3 separate days, they lay prone or supine on a bed with their heads inserted through the side of an adjustable immersion tank. Following 10 min of baseline measurements, the water level was raised such that the water immersed the dorsum, face, or whole head, with the immersion period lasting 60 min. During the first 30 min, the core (esophageal) cooling rate increased from dorsum (0.29 ± 0.2 °C·h–1) to face (0.47 ± 0.1 °C·h–1) to whole head (0.69 ± 0.2 °C·h–1) (p < 0.001); cooling rates were similar during the final 30 min (mean, 0.16 ± 0.1 °C·h–1). During the first 30 min, fingertip blood flow (laser Doppler flux as percent of baseline) decreased faster in whole-head immersion (114 ± 52%·h–1) than in either facial (51 ± 47%·h–1) or dorsal (41 ± 55%·h–1) immersion (p < 0.03); rates of flow decrease were similar during minutes 30 to 60 (mean, 22.5 ± 19%·h–1). Total head heat loss over 60 min was significantly different between whole-head (120.5 ± 13 kJ), facial (86.8 ± 17 kJ), and dorsal (46.0 ± 11 kJ) immersion (p < 0.001). The rate of core cooling, relative to head heat loss, was similar in all conditions (mean, 0.0037 ± 0.001 °C·kJ–1). Although the whole head elicited a higher rate of vasoconstriction, the face did not elicit more vasoconstriction than the dorsum. Rather, the progressive increase in core cooling from dorsal to facial to whole-head immersion simply correlates with increased heat loss.

Infrared-monitored cold response in the assessment of Raynaud's phenomenon

BACKGROUND

Evaluation of treatments for Raynaud's phenomenon (RP) requires objective response parameters in addition to clinical activity scores. Thermographic monitoring of fingertip re-warming after cold challenge has been widely used but usually requires sophisticated equipment. We have previously shown that fingertip re-warming after cold challenge follows a first-order transient response curve that can be described by a single variable, designated tau.

OBJECTIVES

Here, we describe a novel device termed a duosensor, which records the tau value upon cold challenge in an automated manner.

METHODS

We determined tau values in healthy probands, patients with primary or secondary RP associated with autoimmune disease and patients with scleroderma-associated RP following cold challenge, to determine assay variability, sensitivity and specificity.

RESULTS

Duosensor-based thermography exhibited low intraindividual variability in healthy probands. As expected, tau values in RP patients were significantly increased compared with controls (8.08 +/- 3.65 min vs. 3.23 +/- 1.65 min). The duosensor-determined tau value yielded a specificity of 94.6% and predictive value of 95.3% for the presence of RP in a retrospective analysis of 139 patients. Furthermore, in a cohort of scleroderma patients with RP, patient self-assessment of RP severity correlated with tau values.

CONCLUSIONS

Taken together, the present data suggest that tau value determination provides a suitable outcome measure for clinical studies of novel RP treatments. As the duosensor is a simple stand-alone device requiring no supporting equipment and minimal personnel attention, it should allow RP activity monitoring even in clinical settings with minimal technical infrastructure.

Thermosensitive lichen amyloidosis

BACKGROUND

A 26-year-old male presented with a 3-year history of lichen amyloidosis. On examination, there was a pigmented papular eruption with a ripple pattern affecting the limbs and trunk but sparing the axillae, antecubital and popliteal fossae, central chest, neck and face. There was also prominent sparing of the skin overlying the superficial veins of the limbs. The sparing of the superficial veins of the limbs by lichen amyloidosis raised the possible role of cutaneous temperature in governing the distribution of amyloid deposits in our patient.

OBSERVATIONS

Total body infrared thermography demonstrated consistent sparing of the amyloid deposits in areas with higher cutaneous temperatures such as the neck and axillae as well as the course of the superficial veins. The cooler areas such as the extensor surfaces of the arms and legs corresponded to areas of amyloid deposition. Narrow band ultraviolet B (NBUVB) phototherapy over a 5-month period resulted in a marked improvement of pruritus and clearing of the amyloid deposits.

CONCLUSIONS

Our patient clearly demonstrated lichen amyloidosis in a thermosensitive distribution. This may be a gross manifestation of previous reports of in vitro thermosensitivity of amyloid fibril formation and may have potential implications in treatment at least in a subset of patients demonstrating this clinical feature.

Raynaud&#x0027;s phenomenon: Infrared functional imaging applied to diagnosis and drug effects

A non-invasive, innovative approach to the study of Raynaud&#x0027;s Phenomenon is proposed. A group of patients, with respect of a control group, underwent a simultaneous assessment of thermal properties of all ten fingers using infrared functional imaging (IRFI). The assessment highlighted a quite different behaviour between patients with Primary- (PRP) and those with scleroderma - Raynaud&#x0027;s Phenomenon (SSc) and, compared with other existing techniques, seems to be an objective and effective tool to discriminate between PRP and RP secondary to SSc. 18 healthy volunteers (Norm), 20 Primary Raynaud&#x0027;s Phenomenon (PRP) and 20 Secondary Scleroderma (SSc) patients were studied subsequently to clinical evaluation and nail fold capillaroscopy. High-resolution infrared imaging of finger re-warming processes, immediately after a 2 min cold stress, allowed to identify objective parameters. Temperature integral Q (the temperature evaluation of the area under the time-temperature curve along the re-warming period) provided particularly effective figures in describing thermal properties of the fingers. Grand average Q values were (383.4 &#x2213; 12.5) &#x00B0;C×min, (502.9 &#x00B1; 88.1) &#x00B0;C×min and (1022.0 &#x00B1; 110.2) &#x00B0;C×min for the PRP, SSc and Normal groups, respectively. Separate evaluation of the temperature integral for each finger leads to very similar results for the fingers of all the PRP patients; a different thermoregulatory response was observed in SSc patients. The sensitivity of the method in order to distinguish healthy from ill fingers was 100&#x0025;. The specificity in distinguishing SSc from PRP was 95&#x0025;. In addition, IRFI parameters provided a better understanding of the impaired control of the finger&#x0027;s temperature in PRP and SSc with respect to the Normal group. This pilot study also applied IRFI for the measurement of drug effects in patients with Raynaud&#x0027;s Phenomenon. Sixteen out of twenty SSc patients were tested in a single 1-hour session of N-acetylcysteine infusion. IRFI clearly documented a significant increase of face and hands temperature during the drug administration. The grand average value of the finger&#x0027;s temperature after the 1 hour NAC administration was (29.6 &#x00B1; 3.7) &#x00B0;C, while its value before was (27.9 &#x00B1; 3.7) &#x00B0;C (p&#x003C;0.001). N-acetylcysteine seems to act as a vasodilator in patients with Raynaud&#x0027;s phenomenon secondary to systemic sclerosis (scleroderma).