Longitudinal development of skin involvement and reliability of high frequency ultrasound in systemic sclerosis

Abstract

Background: Measurement of skin involvement is essential for diagnosis and prognosis in systemic sclerosis. Assessment by palpation skin score is the current method. Objective: To explore high frequency ultrasound as an objective method to improve skin characterisation by combining measurements of skin thickness and echogenicity. Methods: Skin thickness and echogenicity were measured at the proximal phalanx of the second digit, the back of the hand, the forearm, and the lower leg and, in order to separate limited (lSSc) from diffuse SSc (dSSc), at the chest in 16 patients with early disease and in 16 controls. Measurements were repeated in each patient three or four times with an interval of 1-2 years. Ultrasound measurements of skin thickness were compared with the palpation skin score. Results: Compared with controls, the skin was thickened on the phalanx, hand, forearm, and chest of patients with dSSc, but not patients with lSSc, at the 1 year examination. In dSSc the degree of thickening tended to diminish with time, and at 4 years, thickness was significantly decreased on the forearm and chest compared with the 1 year measurements. Low reflectancy was most pronounced at the 1 year evaluation on the forearm, hand, and phalanx in dSSc, and on the phalanx in lSSc. Conclusion: Separate measurements of skin thickness and echogenicity by high frequency ultrasound add a new dimension to the assessment of skin involvement in SSc, and this seems to be an objective noninvasive tool for use in the study of disease development and in clinical trials.

The use of doppler ultrasound to evaluate lesions of localized scleroderma

“…Ultrasound can document skin thickening associated with SSc, and a good correlation has been found between clinical assessment of skin hardness (modifi ed Rodnan skin score [mRSS]) and ultrasound skin thickness measurements [9,10•]. Ultrasound has demonstrated a shift in dermis echogenicity during the SSc disease course, with initial hypoechogenicity followed by normal to increased echogenicity [11]. This pattern likely represents the early edematous disease phase followed by later progressive fi brosis [10•,11], as dermal edema has been shown to manifest as hypoechogenicity on ultrasound [12].…”

Outcome measures in systemic sclerosis: An update on instruments and current research

“…USG is able to differentiate between healthy controls and people with diffuse SSc [16,17], but skin USG was not able to differentiate between healthy controls and limited SSc in one study [17]. In the same study [17], a lack of association between MRSS and skin thickness assessed by USG was seen. USG has acceptable inter-and intraobserver reliability [16,17].…”

The relationship between the degree of skin fibrosis by sonoelastography and the degree of pulmonary involvement in scleroderma

“…Skin thickness assessment by palpation (modified Rodnan skin score) is widely used in SSc, but it is a qualitative method and has interobserver variability. High-frequency ultrasound has been suggested for the determination of skin thickness and echogenicity (16,19). However, it is not useful for assessment of skin elasticity.…”