Different microvascular involvement in dermatomyositis and systemic sclerosis. A preliminary study by a tight videocapillaroscopic assessment.

OBJECTIVES To observe for changes in capillary morphology and architecture by tight sequential videocapillaroscopic (VCP) assessment in patients with dermatomyositis (DM) and systemic sclerosis (SSc). METHODS VCP examination was performed in 6 patients with DM and 9 with SSc, at baseline and after one month for three times. Four consecutive fields were examined bilaterally for any single finger (from 2nd to 5th). The best visible image per each digit was selected and images from baseline and follow-up were analysed as a sequence, to allow the same capillaries to be tracked and re-assessed. The following abnormalities were identified: homogeneous enlarged capillaries, giant capillaries, irregularly enlarged capillaries, microhaemorrhages, microaneurysms and neoangiogenesis. Capillary density was also considered. RESULTS A significant progressive change of the following abnormalities was detected in DM patients with respect to SSc patients: microhaemorrhages (p=0.009), avascular areas (p=0.024), neoangiogenesis (p=0.001), microaneurysms (0.001), and irregular enlarged capillaries (p=0.044). No significant differences were found for homogeneous enlarged capillaries (p=0.140), giant capillaries (p=1.0) and hairpin/crossed capillaries (0.516). CONCLUSIONS Our preliminary study demonstrated a rapid change of the capillary morphology and architecture in DM with respect to SSc patients. Additional investigations involving larger series of patients may be useful to support more strongly our observations.