Objective: To determine whether sex plays a role in the time to diagnosis of systemic sclerosis (SSc).
Methods: In the Canadian Scleroderma Research Group registry, dates of onset of Raynaud's phenomenon, the first non-Raynaud's disease symptom, and diagnosis were recorded based on patient reports. Association between sex and time to diagnosis was assessed for the group as a whole and stratified based on extent of skin involvement, either limited or diffuse.
Results: Of the 408 patients studied (347 women, 61 men, 44% with diffuse cutaneous SSc), the time to diagnosis after the onset of Raynaud's phenomenon was significantly longer for women than men (log rank P = 0.001), but not significantly different after the onset of the first non-Raynaud's disease manifestation. In an analysis stratified by limited or diffuse status, the time to diagnosis from onset of Raynaud's phenomenon was also significantly longer for women than men with diffuse cutaneous SSc (log rank P = 0.008). A trend toward a longer period between onset of Raynaud's phenomenon and SSc diagnosis was observed in women compared with men with limited cutaneous SSc (median 4.6 years in women versus 2.1 years in men; P = 0.085), and there was no sex difference in time to diagnosis after the onset of the first non-Raynaud's disease manifestation.
Conclusion: In SSc, the time to diagnosis is longer for women than men after the onset of Raynaud's phenomenon, suggesting that there may be possible biologic differences in the progression of disease or in the health care trajectories of men and women with early SSc.