Examination of skin flora in Behçet's patients with positive and negative pathergy test

Aim: Research on the role of viruses and bacteria in the etiopathogenesis of Behçet syndrome has been known for a long time. Reduced bacterial diversity in the oral microbiome and gut microbiome was previously demonstrated in patients with Behçet's syndrome and inflammatory bowel disease. Studies that examined the skin flora in patients with Behçet's syndrome were not previously available. This study aimed to determine the skin flora of patients with positive and negative pathergy test. Method: The skin flora of 30 patients with a positive pathergy test and 30 patients with a negative pathergy test who met the ISG criteria and were followed in the IUC- CTF Rheumatology outpatient clinic were compared with bacterial and fungal analysis methods. Results: As a result of alpha diversity analysis, no significant difference was detected between the bacterial diversities of the pathergy positive and negative groups (p = 0,739). Bacteriai diversity was high in both groups. Beta diversity analysis revealed that the bacteria in the two groups were different from each other in terms of genus and species (p = 0,02). While the pathergy negative group was found to be rich in Betaproteobacteria, Burkholderiales, and Ralstonia picketti, it was shown that Nevskia soli, Staphylococcus haemolyticus, and Sphingomonas sanxanigenens were enriched in the pathergy positive group. As a result of alpha diversity analysis performed to evaluate fungal diversity, it was determined that the diversty of fungal species was higher in the pathergy positive group (p = 0,035). Beta diversity analysis showed that the fungi of both groups were similar (p = 0,34). While Pseudopezicula tracheiphila and Aspergillus heterocaryoticus were detected more abundantly in the pathergy positive group, Aspergillus subversicolor was observed more abundantly in the pathergy negative group. Conclusion: It was determined that the skin microbiota was different among pathergy positive and negative BS patients. Bacterial diversity was found to be high and species of bacteria were different among the two groups. Fungal diversity was higher in the pathergy positive group and there were similar fungi in terms of genus in both groups.