Microscopic inflammatory changes in colon of patients with both active psoriasis and psoriatic arthritis without bowel symptoms

Objective, To evaluate colonic mucosa of patients with both active psoriasi s and psoriatic arthritis (PsA) without bowel symptoms. Methods. Fifteen persons (9 men, 6 women) who had both active psoriasis and PsA without bowel symptoms underwent colonoscopy with multiple biopsies of bowel mucosa. Ten nonhospitalized healthy subjects in followup colonoscopy after resection of benign polyps (8 men, 2 women) took part as a control g roup. Results. Six psoriatic patients (40%) showed macroscopically normal colonic mucosa. In the remaining 9 reddening was frequently recorded (6 cases), wh ile edema and granular changes appeared less commonly (3 cases each, respec tively). Friability was markedly rare (only one case) and bleeding and ulce rations were absent. All 15 patients showed microscopic changes. Increase i n lamina propria cellularity (consisting of plasma cells and lymphocytes) a nd lymphoid aggregates were found in all cases. Active inflammation, eviden t as neutrophilic polymorph infiltration occurred in 9 patients. Glandular atrophy was found in 3 cases; mucosal surface changes and crypt abnormaliti es occurred in one case each. No control had macroscopic or microscopic inf lammatory changes of bowel mucosa. Conclusion. Bowel mucosa of patients with PsA without bowel symptoms show m icroscopic lesions even when mucosa appeared macroscopically normal. This r esult may support a pathogenetic link between skin, joints, and gut in psor iatic patients with arthritis even in the absence of bowel symptoms.