Thermal Disparity between Fingers after Cold-water Immersion of Hands: A Useful Indicator of Disturbed Peripheral Circulation in Raynaud Phenomenon Patients

Abstract

Objective To devise an effective method to assess the peripheral circulation using an infrared thermographic analysis. Methods Sequential measurements of the skin temperature before and after cold-water immersion of the hands were analyzed by a thermographic examination in healthy controls and patients diagnosed to have Raynaud phenomenon (RP). The skin temperatures of the dorsum of all fingernail folds and the metacarpophalangeal (MCP) joints were measured at baseline. Then the hands were immersed in 10°C water for 10 s, and the skin temperatures were measured at 0, 3, 5, 10, 15, 20 and 30 min after immersion. The mean temperature, recovery rate and disparity (coefficient of variation) of the nail fold temperatures were calculated. The distal-dorsal difference (DDD) was calculated by subtracting the mean MCP temperature from the mean nail fold temperature. Receiver operating characteristic (ROC) curves were generated to compare these parameters in terms of their capability to differentiate patients with RP. Results Thirty-one RP patients and 25 controls were included in the study. The baseline nail fold temperature was significantly lower in RP patients than in the controls. The RP patients had a lower recovery rate, lower DDD and higher disparity than the controls. The disparity and DDD were negatively correlated (r=-0.63, p<0.01), whereas the recovery rate and DDD were positively correlated (r=0.91, p<0.01). The ROC curve analysis revealed that the disparity in nail fold temperature effectively differentiated RP patients from controls (area under the curve: recovery rate 0.72; disparity 0.88; DDD 0.79). Conclusion The temperature disparity between fingers is a useful thermographic parameter for evaluating disturbed peripheral circulation in patients with Raynaud phenomenon.

Termografia Aplicada Na Identificação Do Fenômeno De Raynaud

“…Pesquisas apontam recuperação em 10 minutos para grupo controle, sendo a temperatura dos dedos maiores que da região metacárpica [17], [18], [22], [23].…”

The Established and Evolving Role of Nailfold Capillaroscopy in Connective-Tissue Disease

“…The equipment is relatively expensive and requires regular calibration but technology is advancing and soon thermal cameras may be available as smartphone attachments. Several studies have shown thermography to be able to differentiate between healthy controls and primary Raynaud's and between primary Raynaud's and Raynaud's secondary to systemic sclerosis based upon an abnormal pattern (a persistent "distal-dorsal difference") of rewarming [71,72]. Although thermography as a stand-alone test has some utility, further work may help establish that, in time, assessments of patients with potential CTD may include both a structural assessment in the form of NFC and a functional assessment.…”

Infrared thermal imaging in connective tissue diseases

“…Several studies report that IRT can help detect RP [10][11][12]. In healthy subjects, the fingers, especially the finger tips, are usually warmer than the hand.…”

“…In pRP patients, rewarming is slightly delayed compared to unaffected subjects, while in sRP the hands remain cold for a prolonged time. Some authors, however, question the value of cold challenge, suggesting that baseline thermograms have enough discriminatory power for RP diagnosis [10,15].…”