PYODERMA FISTULANS SINIFICA (FOX DEN DISEASE) - A DISTINCTIVE SOFT-TISSUE INFECTION

Pyoderma fistulans sinifica (PFS, also referred to as fox den disease because its multiple fistulae and sinuses resemble the structure of a fox den) is a distinct chronic infectious disease in which epitheliali zed tracts form within the subdermal fatty tissue. PFS, which has not been previously described in the English-language literature, must be differentiated from hidradenitis suppurativa, pilonidal sinus, and per ianal fistula. The fistulous tracts of PFS are always lined by stratif ied squamous-cell epithelium but, unlike those of hidradenitis, reach deep into the subcutaneous fat, run epifascially for long distances, a nd have no relation to skin appendices. We report on 10 men (mean age +/- SD, 36 +/- 5 years) with PFS (mean duration +/- SD, 11 +/- 7 years ). Bacterial cultures of affected tissue from these patients yielded a total of 14 facultative and 31 obligate anaerobic species. Treatment consisted of wide en-bloc excision down to the fascia, including all f istulae. Antibiotic therapy temporarily reduced purulent discharge but did not eradicate the infection. Two patients who underwent fistuloto my without wide en-bloc excision developed recurrences.