Pathergy test with a 23G needle with and without self-saliva in patients with Behcet's disease, recurrent aphthous stomatitis and control group compared to the 20G test

Objectives: The pathergy test (PT) is part of the diagnostic criteria of Behcet's disease (BD). Factors like needle character and number of punctures can affect the sensitivity of PT. We tried to compare its pos-itivity using a thinner needle with and without self-saliva in active and inactive BD, recurrent aphthous stomatitis (RAS), and healthy people. Material and methods: Twenty patients with active and 13 with inactive BD, 20 with RAS, and 34 healthy controls underwent 3 types of PT: 1 - the most recommended 20G dry needle PT, 2 - 23G dry needle PT, and 3 - 23G PT with self-saliva. The positivity and diagnostic accuracy of the tests between groups were compared. Results: All tests were negative in the normal healthy group. In active BD, the positivity of PT with self-sa-liva (70%) was higher than the 20G PT (20%) (p-value = 0.004), being more correlated to disease activity (p-value = 0.046). In the RAS group, there was no difference in the positivity of all tests (p-value = 0.068). All tests had high diagnostic accuracy in discriminating between patients with active BD and the controls (p < 0.05). The pathergy test with self-saliva showed significant diagnostic accuracy in discriminating BD from non-BD participants (p < 0.001). The results of dry 23G PT were the same as those of 20G PT. Conclusions: The self-saliva PT test was more positive in patients with active BD, correlated with disease activity, was more sensitive, had equal specificity in detecting BD from the control group, and was more sensitive but less specific in detecting BD, compared to the RAS group. The positivity and accuracy of dry 23G needle PT were the same as the 20G PT. Pathergy test with self-saliva using a thin (23G) needle is more sensitive has equal specificity in detecting patients with BD compared to the control group and is more sensitive but less specific in detecting the patients with BD compared to the RAS group. The positivity and accuracy of dry 23G needle PT is the same as the most recommended 20G dry PT. Pathergy test by wet 23G needle (with self-saliva) is more positive in patients with active BD compared to PT by dry 20G needle.