Images in Clinical Medicine
Interdigital Pilonidal Sinus
N Engl J Med 2004; 350:e10March 11, 2004
- Article
A healthy 39-year-old woman who was employed as an animal groomer presented with a chronic draining cyst in the web between the middle and ring fingers of one hand. The drainage had persisted for five months and had not resolved with oral antibiotic therapy. Examination revealed a small sinus tract with visible hair (Panel A, arrow) and an area of chronic inflammation (arrowhead). An area of chronic inflammatory tissue with a sinus tract and multiple visible hairs was excised (Panel B). Pathological examination of the specimen (Panel C; hematoxylin and eosin, ×40) revealed a sinus tract with abundant keratin (upper left portion of panel), epidermal thickening, dermal fibrosis with chronic inflammation (lower right portion of panel), and multiple embedded hairs (arrows). The drainage and discomfort resolved immediately after the excision.
The word “pilonidal” is derived from the Latin words pilus (meaning hair) and nidus (meaning nest). Pilonidal cysts can occur anywhere in the body and in barbers and animal groomers may be found between the fingers. If coarse hair becomes embedded in an interdigital fold, it may lead to chronic inflammation, the formation of a sinus tract, and chronic, purulent drainage. Surgical removal of the hair and the inflammatory tissue will lead to prompt resolution of the condition.
Peter J. Stern, M.D.
University of Cincinnati, Cincinnati, OH 45206Charles A. Goldfarb, M.D.
Washington University, St. Louis, MO 63105
