Pilonidal cyst - Anogenital in
Initially, pilonidal disease was believed to be congenital in nature and to represent a type of dermoid cyst. Current belief is that this is caused by excessive repetitive trauma to the sacrococcygeal region, illustrated by the prevalence of this problem among Jeep drivers in World War II (so called "Jeep disease").
Risk factors for pilonidal disease include male sex (adult), hirsutism, obesity, occupations requiring extended periods of sitting, and the presence of a deep natal cleft. Pilonidal cysts are more common in adolescence and young adulthood. Systemic signs and symptoms are rare.
"Barber's interdigital pilonidal sinus" refers to the reaction surrounding an entrapped cut or shaved hair, often seen in an interdigital space of a barber's hand. These cases represent foreign body granulomas rather than true cysts.
L05.01 – Pilonidal cyst with abscess
L05.91 – Pilonidal cyst without abscess
47639008 – Pilonidal cyst
Differential Diagnosis & Pitfalls
- Cellulitis or erysipelas
- Fournier gangrene
- Perianal abscess arising from the posterior midline crypt
- Perirectal abscess
- Hidradenitis suppurativa
- Sacral osteomyelitis
- Anal fistula
- Coccygeal sinus
- Cutaneous Crohn disease
- Pyoderma gangrenosum
- Ecthyma gangrenosum
- Presacral sinus or dimple
- Dermal sinus tract – Dermal sinuses are usually found above the gluteal cleft, while pilonidal disease is seen within the gluteal cleft.
- Congenital anomaly (ie, spina bifida occulta)