The association of pathergy reaction and active clinical presentations of Behçet's disease

The pathergy skin test is a hypersensitivity reaction to a prick skin trauma caused by a pin or a needle, which is considered as a specific presentation in Behçet's disease (BD) and the precise mechanism of this test is not well elucidated. This study was designed to evaluate the association of pathergy reaction (PR) with the active clinical manifestations of BD patients, to assess the clinical importance of PR.

This was a cohort study on 1675 BD patients who fulfilled the entry criteria based on the International Criteria for Behçet's Disease (ICBD) from 1975 to 2011. The patients were divided into two groups; the pathergy positive group included 841 patients (50.2%) and the pathergy negative group 834 patients (49.8%). The active mucocutaneous and systemic disease manifestations were analyzed according to the presence of the PR. The odds ratio and 95% confidence interval (95% CI) were calculated for each item.

In this study, 841 patients (50.2%) had a positive pathergy test. Patient's mean age and mean disease duration were similar in the two groups (pathergy positive and pathergy negative patients). There was no association between positive pathergy test and age of patients, or disease duration. The PR was associated with male gender (p = 0.013), oral aphthosis (p < 0.001), pseudofolliculitis (p < 0.001), anterior uveitis (p = 0.001) and posterior uveitis (p = 0.028).

The presence of PR was associated with male gender, as well as some of mucocutaneous manifestations and uveitis in adult patients. There was no association with retinitis and vascular involvements. PR isn't associated with the severity of the disease.