Clinical Profile and Significance of Mucocutaneous Lesions of Primary Sjögren's Syndrome: A Large Cross-sectional Study with 874 Patients

BACKGROUND Mucocutaneous lesions are common features of primary Sjögren's syndrome (pSS), but only a few studies have focused on them. To demonstrate the profile of mucocutaneous lesions of pSS and further explore their potential clinical significance, we performed a cross-sectional study on 874 patients. METHODS Demographic data, clinical manifestations, and laboratory results of 874 pSS patients were collected. Patients were divided into two groups according to the presence of mucocutaneous lesions. Differences in primary symptoms and systemic impairments between the two groups were analyzed. Results of laboratory tests were also compared after excluding those who had taken corticosteroid from both groups. One-year follow-up was done, and occurrences of various new complications were compared. RESULTS Among the 874 pSS patients, 181 patients had mucocutaneous lesions, accounting for 20.7%. Multiple mucocutaneous manifestations were displayed, and the top four most common types of lesions were purpuric eruptions (39.8%), urticaria (23.8%), Raynaud's phenomenon (14.9%), and angular stomatitis (9.9%). Incidences of pulmonary interstitial fibrosis, pulmonary bullae, leukopenia, and anemia were significantly higher among patients with mucocutaneous lesions (P < 0.05). Increase in IgG and decrease in C4 among patients with mucocutaneous lesions displayed statistical significance after excluding patients from both groups who had taken corticosteroid (P < 0.05). After one-year follow-up, patients with mucocutaneous lesions presented a slightly higher incidence of new complications compared to those without. CONCLUSIONS Mucocutaneous manifestations of pSS patients were common and diverse. Patients with mucocutaneous manifestations had more systemic damages, higher level of IgG, and lower level of serum C4, suggesting a higher activity of the primary disease.