Pilonidal granuloma formation after an incision and drainage procedure is associated with retained hair within the sinus – A case series

Abstract

Introduction and importance

Pilonidal disease may present with a draining secondary sinus or granuloma, but the development of these findings is not well-characterized.

Case presentation

Two adolescent males presented with pilonidal disease. The first patient had a gluteal cleft abscess, and an incision and drainage procedure was performed. Although the abscess resolved, the incision site formed a granuloma with intermittent draining wound with granulation tissue. He underwent a pit-picking procedure along with excision of the granuloma. A large amount of hair was also removed from within the pilonidal sinus. The second patient underwent an incision and drainage procedure to treat the pilonidal abscess. The incision site evolved into a granuloma with recurring drainage. A pit-picking procedure was performed, and the granuloma was excised. During the excision, a moderate amount of hair was evacuated from the pilonidal sinus.

Clinical discussion

Many pilonidal patients present with a granuloma or secondary sinus at the gluteal cleft, but there has been no documentation of the natural history of this development. The role of hair is central to pilonidal disease pathophysiology and is a known factor in foreign body granuloma formation – a cutaneous inflammatory response to endogenous or exogenous material in the dermis that is not broken down readily by macrophages.

Conclusion

Even though the pilonidal abscess was drained with an incision, a granuloma was able to form with recurrent drainage when hair was retained within the pilonidal sinus.