Pilonidal cyst is a pit or abscess near the tailbone that often contains hair and skin debris. They are more common in men than women and affect younger adults between the ages of 20-40. It can have a variety of presentations, from a small painless pit to a large, painful abscess.
There is usually a small hole that occasionally drains clear fluid when the cyst is not inflamed. When the cyst becomes infected or inflamed, it becomes red, swollen, painful, and may drain pus or blood. People with inflamed or infected pilonidal cysts may have fevers, chills or swollen lymph nodes. In chronic and recurrent pilonidal cysts, a 2-5cm tunnel may form under the skin, and may be filled with fluid drainage.
People who are at risk for getting pilonidal cysts typically have the following:
- thick and curly hair
- poor hygiene
- long periods of sitting
- chronic buttock friction
- increased sweating
- hidradenitis suppurativa
The exact cause of pilonidal cysts is unknown. Some possible causes include:
- Chronic bacterial infection.
- Some people are born with small pits near the base of the spine due to a genetic problem or developmental complication in the womb.
- Repeated friction near the buttock may irritate the hair follicles or cause the hair to poke through the wall of the hair follicle, which leads to follicle inflammation followed by cyst formation.
- People who have a medical condition called Follicular Occlusion Syndrome are prone to cysts and acne-like skin problems, including pilonidal cysts.
Pilonidal cysts that do not drain or cause problems do not require treatment. Problematic pilonidal cysts may be treated with:
- Oral antibiotics when they are infected with bacteria.
- Surgical removal of the cyst.
- Laser hair reduction may decrease the frequency of cyst inflammation and infection.