The role of nailbed vasospasm in Crohn's disease.

Local cooling of the nailfold capillaries produces a typical blood flow stop reaction in patients with Raynaud's phenomenon. We applied the same test to 35 patients with Crohn's disease and compared the results with the findings in a control group of 35 healthy subjects matched for age and sex by nailfold videomicroscopy. We found a flow stop with cold exposure in 27 of the 35 patients with Crohn's disease (mean duration 38 s) in contrast to 2 of the 35 control subjects only (mean duration 12 s). There was no significant difference in skin temperature between the two groups. Intravital microscopy of nailfold capillaries revealed an evident reduction of the capillary density (p = 0.001) and crest diameter of the capillary loop (p = 0.02) compared to normal subjects. The strong association of a vasoconstrictive reaction in finger microcirculation in patients with Crohn's disease suggests a vasospastic tendency in this disorder that might manifest in the mesenteric capillaries also. This new finding of microcirculatory disturbance may play a role in the pathophysiology of Crohn's disease and be related to a general vasospastic syndrome.