Is collagenous colitis a new etiology of sicca syndrome?

We conducted a prospective cross-sectional study of seven patients with collagenous colitis to determine the clinical, immunologic and histologic features of sicca syndrome associated with this condition. Four patients reported dryness of the mouth and/or eyes. No laboratory evidence of autoimmune disease was found, except in one patient with ankylosing spondylitis. Collagenous infiltration of the salivary glands was quantified in each patient as the percentage of the total gland surface examined. Histologic studies of salivary glands demonstrated significantly more collagen in the group of patients with collagenous colitis than in the group of age-matched controls (30.52% versus 11.8%, p < 0.05). No inflammatory infiltrates were seen. Our data suggest that a common mechanism may underlie the various lesions found in patients with collagenous colitis. However, the mechanism that initiates the fibrotic process in the colon and salivary glands remains unknown.