Genital aphthosis in Behçet's disease: is it associated with less eye involvement?

Behçet's disease (BD) is a multisystem disease classified among the vasculitides with various clinical features. Genital aphthosis (GA) is one of the major manifestations of BD. The aim of this study was to evaluate the characteristics of BD patients with GA. A cross-sectional sample of BD patients registered in 37 years was selected. We determined clinical and laboratory features of BD patients with GA (GA cases) and compared them with the patients who never developed GA (non-GA cases). The comparisons were performed by the chi-square test and logistic regression analysis. Odds ratios (ORs) with 95 % confidence intervals were calculated to estimate the precision of ORs. Among 6,935 BD patients, 4,489 cases (64.7 %) were ascribed to GA cases. Male to female ratio (1.11:1.00 vs. 1.48:1.00 OR 0.753, P value <0.001) and mean age of disease onset (OR = 0.9, P value <0.001) were lower in GA subset. In GA cases, oral aphthosis (OA) was a more common onset manifestation (OR 2.250, P value <0.001), while uveitis (OR 0.140, P value <0.001) and retinal vasculitis (OR 0.077, P value <0.001) were less common at the disease onset. In the whole course of disease, eye involvement was less common in GA cases (OR 0.215, P value <0.001). On the contrary, OA (OR 19.698, P value <0.001), skin (OR 1.762, P value <0.001), joint (OR 1.257, P value = 0.001), gastrointestinal (OR 1.302, P value = 0.009), neurological (OR 1.624, P value <0.001) and vascular involvements (OR 1.362, P value <0.001), epididymitis (OR 1.596, P value <0.001), positive pathergy test (OR 1.209, P value <0.001) and positive familial history of OA (OR 1.325, P value <0.001) were more common in GA subset. This study showed that GA subset of BD is associated with less eye involvement but higher rates of other BD manifestations.