Expression of Epstein-Barr virus in children with sacrococcygeal pilonidal sinus determined by immunohistochemical methods

In this study, we probed whether chronic infections of skin such as pilonidal sinus could be a potential site of Epstein–Barr virus (EBV) replication. Pilonidal sinus is associated with a high recurrence rate. Therefore, we decided to determine the role of EBV's presence to explain whether it is correlated with the recurrence of pilonidal sinuses. This study was conducted on 36 patient samples with sacrococcygeal pilonidal sinus. Samples were immunohistochemically stained for EBV, CD3 and CD20 expression. Thirty‐six adolescents with pilonidal disease were evaluated. EBV‐positive cells were located in dermis with high inflammatory activity. EBV‐positive cells stained positive for the B‐cell antigen CD20 and were detected in 10 of 36 (27%) pilonidal sinus specimens. Among those who had experienced a relapse, three were positive for EBV expression. In addition, EBV expression was detected in eight cases with severe inflammation, and in two with minimal or moderate inflammation. Our study advances the field by demonstrating that similar to gastrointestinal mucosa, skin could be a reservoir for EBV. EBV was found to be restricted to B cells in skin lesions, and it was found that skin lesions with severe inflammation showed higher frequency of EBV expression in comparison to minimal or moderately inflammed skin lesions. Additionally, recurrence was more frequently observed among EBV‐positive cases. These findings point out for a role of EBV infection in the recurrence of pilonidal sinuses.