The pilonidal cyst and tailbone fistula can be confused with a number of other diseases. These primarily include fistula formation from the anus (anal fistulae) and fistulae that can occur in chronic inflammatory intestinal diseases such as Crohn's disease. Fistula diseases in the buttocks can also be caused by acne inversa. This is a chronic skin disease based on inflammation of the sebaceous glands and hair roots.
Rhagades can also imitate a pilonidal disease. These are narrow, slit-shaped tears in the skin due to overstretching. Psoriasis is also one of the differential diagnoses.
Literature sources:
Steinemann D, Dindo D et al (2011) Pilonidalsinus und Analfistel. Coloproctology 33:160–170
Breuninger H (2004) Treatment of pilonidal sinus and acne inversa. Hautarzt 55:254–258
Stelzner F (1984) Die Ursache des Pilonidalsinus und der Pyodermia fistulans sinifica. Langenbecks Arch Chir 362:105–118
Laffert M von, Stadie V et al (2011) Morphology of pilonidal sinus disease: some evidence of its being a unilocalized type of hidradenitis suppurativa. Dermatology 223:349–355
Jansen T, Wolff H et al (1996) Eruptive vellus hair cysts. Hautarzt 47:378–381
Alrawashdeh W, Ajaz S et al (2008) Primary anal pilonidal disease. Colorectal Dis 10:303–304
Accarpio G, Davini MD et al (1988) Pilonidal sinus with an anal canal fistula. Report of a case. Dis Colon Rectum 31:965–967
Marra B, Fantini C et al (2005) Management of sacrococcygeal chordoma mimicking a pilonidal sinus: report of a case. Int J Colorectal Dis 20:388– 389
Fitzgerald JE, Lepore M (2012) Idiopathic calcinosis cutis infection as an unusual mimic of pilonidal abscess. ANZ J Surg 82:758–759
Gupta PJ (2008) Tubercular infection in the sacrococcygeal pilonidal sinus – a case report. Int Wound J 5:648–650
Anscombe AR, Hofmeyr J (1954) Perianal actinomycosis complicating pilonidal sinus. Br J Surg 41:666
Alexiou GA, Sfakianos G et al (2012) Myxopapillary ependymoma of the sacrococcygeal region presenting as a pilonidal sinus. Pediatr Neurosurg 48:64–65
