OBJECTIVE: To evaluate the relationship between systemic inflammation and skin microcirculation in patients with rheumatoid arthritis (RA) and ankylosing spondylitis (AS). METHODS: We assessed skin microcirculation flux (laser Doppler flowmetry), classical cardiovascular risk factors, inflammatory markers and disease activity (Disease Activity Score 28, Bath Ankylosing Spondylitis Disease Activity Index) in 75 patients with arthritis with a median disease duration of 4 years, and in 26 healthy subjects. RESULTS: In patients with arthritis inflammatory markers (C-reactive protein, interleukin 6, fibrinogen) were increased, peak flux velocity after the occlusion at the temperature of 36.6 degrees C and maximal heat flux velocity after the heating were significantly lower. These findings were accompanied by the slower increase in the flux rate during local heating. There were positive correlations between inflammatory markers and microcirculation parameters in patients with RA and AS, but only for RA patients between peak flux velocity and disease activity. There were no significant intergroup differences when the classical cardiovascular risk factors were compared except for the lower HDL cholesterol in arthritis patients. CONCLUSIONS: Patients with chronic systemic inflammatory arthritis presented altered microvascular function and reduced vasodilator capacity of the forearm skin microcirculation.