High frequency ultrasound assessment of skin in systemic sclerosis patients

Abstract

To evaluate the role of high frequency ultrasound (HFU) in assessing skin changes in terms of thickness and echogenicity in systemic sclerosis (SSc) patients with early and late changes. Twenty-three SSc patients were enrolled along with 21 matched controls. Skin thickness was assessed using modified Rodnan skin score (mRSS) and HFU. Patients had mean age of 41.8 ± 9.1 years, 91.3% were females, mean disease duration 6.0 ± 4.6 years, 11 patients had early (<5 years) and 12 late (≥5 years) disease, 8 patients had limited (lcSSc) and 15 diffuse (dcSSc) cutaneous SSc. Antinuclear antibody was positive in 17 (73.9%) and antiscleroderma-17 in 18 (78.3%). Patients had significantly thicker skin between second and third metacarpophalangeal joint (L = 1.52 ± 0.35 mm vs 1.25 ± 0.35 mm; p = 0.017 and T = 1.48 ± 0.34 mm vs 1.26 ± 0.33 mm; p = 0.038 respectively). Patients with early disease had thicker skin than those with late disease. HFU dermal thickness showed no significant difference according to gender, subtypes, presence and absence of clinical manifestations or autoantibody positivity. There was significant higher dermal thickness in patients with reflux (p = 0.009) and was lower in patients with interstitial pulmonary fibrosis (p < 0.05). There was negative correlation between US dermal thickness and disease duration (p < 0.05). mRSS showed no correlation with HFU dermal thickness in all areas. HFU is useful in assessing skin pathologic changes (even subclinical changes) in terms of thickness and echogenicity in SSc patients. Moreover, it could be a potential screening tool in differentiating normal from pathologic skin thickness.