The mucosa of the inferior turbinate was studied using rhinostereometry and micromanipulator-guided laser Doppler flowmetry in 10 healthy volunteers. First, spontaneous fluctuations were studied measuring congestion and multiple microcirculatory parameters simultaneously every 2 minutes. The subjects were then challenged with oxymetazoline using the same measuring technique studying the effects of the challenge during 12 minutes. There were spontaneous variations in congestion of up to 2.1 mm and variations in perfusion from 38% to 175% of average. There was no correlation between congestion in itself, or change in congestion, to perfusion or any other microcirculatory parameter. After challenge with oxymetazoline there was a rapid decrease in perfusion at 3 minutes after which there were no significant changes. The congestion decreased gradually throughout the procedure. Because congestion reflects the filling of the venous sinusoids and the flowmetry the state of the superficial vessels, we conclude that there are spontaneous short-term fluctuations in the sympathetic tone with independent actions on the different vessels. After challenge with a sympathomimetic drug, there was a decrease in both swelling and flow, but not synchronized. The combination of rhinostereometry and micromanipulator-guided laser Doppler flowmetry is a useful tool to study the dynamics of intranasal challenge reactions.