Pilonidal Cysts: What Are the Risk Factors?
Most experts believe that the cysts arise due to trauma to the area that
results in ingrown hairs. Pilonidal cysts often contain hair when excised, but
hair follicles have not been demonstrated in them, suggesting that the hair may
have been introduced from outside the cyst. Pilonidal disease was a common
problem among servicemen during World War II, thought to be due to the
mechanical trauma of riding in jeeps, trucks, and tanks.