Characterization of somatosensory profiles in patients with Crohn's disease

Crohn's disease (CD) is a painful chronic inflammatory bowel disease. It primarily affects terminal ileum, but the involvement of large and small intestines or extraintestinal manifestations is very common. CD may go along with neurogenic inflammation, mediated by substance P and CGRP, which are also key players in pain transmission. This may in turn contribute to hyperalgesia and altered somatosensory function in CD.

One hundred and three (103) patients with CD and 80 healthy volunteers were enrolled. Patient characteristics and disease history were documented. We used quantitative sensory testing (QST) to investigate the somatosensory profile in patients and volunteers. We also calculated z-scores for the QST results of the patients with CD based on the data of our control group. A 2-step cluster analysis, using all QST data, was performed to find subgroups within patients and volunteers.

Thresholds of warm detection, mechanical pain, and vibration detection did significantly differ between patients with CD and volunteers. Z-scores indicated a general trend of sensory loss in CD patients with a significant relationship between patients with a sensory loss for cold and warm detection. In the hyposensitive cluster of the CD cohort, patients were more frequently male, had a higher incidence of extraintestinal manifestations, and suffered longer from CD.

Our findings are consistent with the presence of a subclinical small fiber neuropathy. The group of CD patients with pronounced neuropathy findings were predominantly males, had a higher incidence of extraintestinal manifestations, and tended to have a longer history of disease duration.