RESUMO
OBJECTIVES: The objectives of this study were to evaluate the dynamic behaviour of digital skin microvascular blood flow before and after cold stimulation using laser Doppler imaging (LDI) in children and adolescents with RP secondary to juvenile systemic sclerosis (JSS), primary RP (PRP) and healthy controls and to compare functional abnormalities measured by LDI with structural microvascular abnormalities evaluated by nailfold capillaroscopy (NFC). METHODS: Five JSS patients, five children and adolescents with PRP and five healthy controls matched for gender and age were included. All subjects had NFC performed. Finger blood flow (FBF) was measured using the LDI system (Moor Instruments) at baseline and after cold stimulus (CS). RESULTS: There were a decreased number of capillaries, a greater number of enlarged capillaries and a higher deletion score in JSS patients compared with controls and patients with PRP. The mean baseline FBF was significantly lower in JSS patients compared with controls. There was no difference between the mean baseline FBF in JSS patients compared with patients with PRP. There was a significant decrease in FBF 1 min after CS in all groups followed by blood flow recovery at 20 min after CS in comparison with basal FBF values in controls, but not in JSS and PRP patients. CONCLUSION: In JSS patients, LDI showed a lower FBF before and after CS compared with healthy controls and may be an objective and sensitive method for the measurement of digital skin blood flow in RP children.