Calcinosis in systemic sclerosis: subsets, distribution and complications

Objective: To retrospectively analyse the features of calcinosis in a cohort of SSc patients.

Methods: Charts of SSc patients attending the Ulcer Unit of the Rheumatology Department, University of Florence and presenting a clinical suspicion of calcinosis were considered in the study. Data on clinical history, including recent skin changes, and clinical examination of all areas with suspected calcinosis, radiological imaging of the calcinotic area, demographics and SSc-related organ involvement and pain measured by a visual analogue scale were recorded.

Results: In 52 of 112 SSc patients, a total of 316 calcinoses were recorded and were divided into visible and palpable {154 [47.4%], clustered according to their macroscopic features as mousse [49 (31.8%)] and stone [: 105 (68.2%)]} and non-visible but palpable {: 162 [52.6%]: net [5 (3%)], plate [22 (13.8%)] and stone [135 (83.2%)]}. The X-ray-based classification of all calcinoses, both visible and non-visible, was as follows: stone, 289 (91.4%); net, 12 (3.8%) and plate, 15 (4.8%). Skin ulcers complicated 154 of 316 calcinoses (48.7%). Mousse calcinosis was associated with pulmonary arterial hypertension, the stone subset was suggestive of pulmonary involvement and justified further investigation and the net subset was the slowest to heal.

Conclusion: Our data indicate that calcinosis may be classified in SSc as mousse, stone, net and plate according to its clinical and X-ray features. This classification awaits validation for a possible use in clinical practice and to support early treatment and prevention of complications.