Is there a role for laser speckle contrast analysis (LASCA) in predicting the outcome of digital ulcers in patients with systemic sclerosis?

Objective: Digital ulcers (DUs) represent one major burden for patients with systemic sclerosis (SSc). The objectives of our study were to evaluate blood flow in SSc-DUs with laser speckle contrast analysis (LASCA) and to correlate the skin perfusion to clinical and laboratory data.

Methods: Forty DUs in 31 consecutive patients with SSc according to 2013 ACR/EULAR criteria (20 with limited cutaneous disease, 3 males) were prospectively examined with LASCA. Clinical and laboratory data were collected at the same time. DUs were classified according to clinical features and presence of infection.

Results: At LASCA analysis, patients with diffuse SSc had lower mean values of blood flow compared with those with limited disease at the finger affected by DUs (88.80 vs 44.40, p = 0.036) and at the periulcer area (p = 0.041). The presence of infection was associated to a higher flow at the finger with DU (103.02 vs 58.05 p = 0.04), at the level of ulcer (217.63 vs 67.15, p < 0.001), and at the periulcer area (p = 0.001). The ratio between the blood flow at the ulcer area and the finger base (UA/FB) showed a bimodal trend in patients with infected DUs and in those without infections. Infection was positive correlated to the time of healing (HT) (r = 0.648, p = 0.023), while in DUs without infection a negative correlation to HT (r = - 0.46, p = 0.015) was identified.

Conclusions: This study demonstrates for the first time that the UA/FB ratio may predict the healing time of DUs in SSc patients and may be crucial for the prognostic stratification of patients. Infection remains one of the main predictors of DU healing.Key Points• The prognostic value of laser speckle contrast analysis (LASCA) in patients with digital ulcers (DUs) in systemic sclerosis remains to be clarified.• LASCA may be able to predict the haling time of the digital ulcers.• The presence of infection of the wound bed may greatly influence the LASCA parameters and the healing time of the digital ulcer.