Prevalence and clinical association with calcinosis cutis in early systemic sclerosis

Calcinosis cutis is often found with systemic sclerosis (SSc). However the calcinosis cutis and its clinical association among SSc patients is limited. Our aims were to assess the prevalence of calcinosis cutis and its association with clinical features of SSc patients at early onset of the disease.

A cross-sectional study on clinical characteristics and hand radiographs of 120 newly diagnosed SSc patients with the onset less than four years were evaluated. Calcinosis cutis was described based on the anatomical regions, density (level 1-3) and shapes (net, plate, stone, and amorphous).

Among all SSc patients enrolled, 62.5% were females and 56.1% were diffuse cutaneous SSc. The mean disease duration was 2.0 ± 1.3 years. Calcinosis cutis was detected in 60 patients with the prevalence of 50% (95%confidence interval (CI), 0.41-0.59), of which 53.3% occurred at distal phalanx, 96.7% had stone shape and 48.3% were high density. Univariate analysis revealed that calcinosis cutis was associated with age (p = .02) and high-density calcinosis cutis was associated with Raynaud's phenomenon (p = .02), ischemic ulcer (p = .04), and telangiectasis (p = .02). Logistic regression analysis revealed that calcinosis cutis at distal phalanx was negatively associated with edema at the onset (odds ratio, 0.09).

Occult calcinosis cutis can be detected by hand radiograph in one half of SSc patients at early onset of the disease. Elderly patient has a risk for calcinosis cutis development and Raynaud's phenomenon was associated with high density calcinosis cutis. Calcinosis cutis, particularly at distal phalanx was less likely to be detected in an edematous phase of disease.