Prevalence of sicca symptoms in a South Australian cohort with systemic sclerosis

Background: The presence of sicca symptoms is a frequent finding in patients with systemic sclerosis (SSc). The aim of this study was to examine the prevalence of sicca symptoms in a South Australian cohort of SSc patients and correlate this to a number of parameters, including autoantibody status, use of anticholinergic medication, age and the presence of functional anti‐muscarinic‐3 receptor (M3R)‐blocking antibodies. Methods: A screening questionnaire was sent out to all patients on the South Australian Scleroderma Register from the years 1998–2006 to determine the prevalence of sicca symptoms. A subset of patients on the register had ocular sicca symptoms tested by use of Schirmer’s strips to validate the accuracy of the questionnaire. Eight patients were tested for anti‐M3R‐blocking antibodies using a functional physiological assay. Results: One hundred and ninety‐three SSc patients took part in this study. Sicca symptoms were present in 59% of patients with the limited form of SSc, compared with 49% of patients with the diffuse form and 40% of patients with the overlap syndrome. The use of anticholinergic medication or thyroxine was associated with higher sicca scores in SSc patients. SS‐A and SS‐B autoantibodies (seen in Sjögren’s syndrome) were detected in eight patients in this study. The detection of anti‐M3R‐blocking antibodies correlated well to presence of sicca. Conclusion: This study confirmed that sicca symptoms are found in a high proportion of patients with SSc, especially those with the limited variant. Further testing of larger numbers of SSc patients with sicca for anti‐M3R‐blocking antibodies will be needed before more definitive conclusions can be drawn. Physicians should be made aware that sicca symptoms are a frequent cause of morbidity for SSc patients * .