A pilonidal sinus is a small cyst that occurs in the cleft, the top part of the buttocks. Usually, a pilonidal sinus consists of hair, debris and dirt. It can catch infections and cause severe pain. With infection, it can ooze pus, blood and have foul odor.
When the process begins, there might not be any noticeable symptom but for a small dimple near the top part of the buttocks. If it gets infected, the depression might turn into a cyst or an abscess. A cyst is a closed sac filled with fluid, whereas an abscess is a swollen and inflamed tissue where pus gets collected. If you have an infection, the symptoms are:
Activities like sitting cause friction and prompt the growing hair in the buttocks, into going back into the skin. When hair retracts back to the skin, the body considers hair as foreign particles and launches an immune response against the hair. Because of this immunization process, a cyst gets formed around the hair. Although the root cause for pilonidal sinus has not been established for certain, the factors that contribute to it are:
The ways to prevent pilonidal sinus are: