Objectives To determine the prevalence, clinical characteristics and radiographic findings of hand abnormalities in SSc patients in a cross sectional study, as well as to compare those differences among SSc subgroups.
Methods SSc patients who were followed-up at the Rheumatology clinic, Chiang Mai University from June 2012 to June 2013 were consecutively invited. After study entry, demographic data, clinical features, hand involvement, heath assessment questionnaire (HAQ), current treatment, serologic investigation, and hand radiograph were evaluated. The radiographic assessment was performed by one investigator blinded to the clinical. Modified Sharp score was used to determine the severity of joint involvement.
Results 110 SSc patients with mean (SD) age, 53.2 (9.2) years; median disease duration (IQR), 3.0 (2.0, 6.2) years were studied. Of them, 75 (68.2%) patients were female and 73 (66.4%) were classified as diffuse cutaneous SSc (DcSSc). Mean (SD) age and median (IQR) disease duration were comparable among DcSSc and limited cutaneous SSc (LcSSc) subgroups; (53.2 (9.8) vs. 53.1 (8.0)) years, and (3.0 (2, 6) vs. 3.0 (2, 8.5)) years, respectively. There were interstitial lung disease in 73.6% and pulmonary artery hypertension in 10.9% of study patients. Hand abnormalities in SSc included Raynaud's phenomenon (89.1%), digital pitting scar (44.5%), flexion contracture (42.7%), acrolysis (36.4%), arthralgia (30.9%), digital ulcer (12.7%), traumatic ulcer (12.8%), telangiectasia (12.7%), arthritis (9.1%), and tendon friction rub (0.9%). Median (IQR) hand HAQ was 0.3 (0, 1). Anti-Scl-70 antibody and rheumatoid factor were present in 74.5% and 7.3%, respectively. Radiological abnormalities included acro-osteolysis (57.3%), paraarticular calcification (24.5%), joint subluxation (16.4%), flexion contracture (10.9%), joint space narrowing (9.1%), joint erosion (7.3%), and soft tissue calcification (7.3%). Median (range) modified Sharp score consisted of total score, joint erosion score, and joint space narrowing score were 0 (0-201), 0 (0-89), and 0 (0-112), respectively. DcSSc patients had significantly more hand complications including digital pitting scar (53.4% vs. 27.0%, p<0.01), digital ulcer (17.8% vs. 2.7%, p=0.03), traumatic ulcer (27.4% vs. 0%, p<0.01), acrolysis (45.2% vs. 18.9%, p<0.01), and flexion contracture (60.3% vs. 8.1%, p<0.01) than LcSSc. The Modified Rodnan skin score of fingers and hands of DcSSc were significantly higher than LcSSc (5.8 (3.1) vs. 2.8 (1.8), p<0.001). On hand radiography, DcSSc patients also had more acro-osteolysis (65.7% vs. 45.9%, p<0.05) and flexion contracture (16.4% vs. 0%, p<0.01). However, there were no significant differences of the scores including hand HAQ, pain VAS, and modified Sharp score among subgroups.
Conclusions Hand abnormalities are common in SSc patients, especially in patients with DcSSc subtype. The most common clinical and radiological hand complications of our study population were digital pitting scar and acro-osteolysis, respectively. Further study focusing on early treatment of vascular injury in such lesions is needed to prevent these complications.
Disclosure of Interest None declared