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