Pilonidal disease is one of those conditions that most people have never heard of until they have it. Then it becomes hard to ignore. Often affecting young adults, particularly men, it typically appears as a painful swelling or abscess near the top of the buttocks, just above the cleft. For some, it resolves with minor treatment, while for others it can become a chronic cycle of flare-ups and infections requiring surgery.
It’s long been known that hair plays a role in the development of pilonidal disease. A new UK Biobank study has identified a gene linked to hair growth and patterning that appears to significantly raise a person’s risk.
It’s a step forward in understanding what has often felt like a mysterious condition, and it may help shape how we approach treatment and prevention in the future.
What is pilonidal disease?
Pilonidal disease occurs when hairs, usually coarse body hair, become trapped in the skin near the sacrum (just above the buttocks). These stray hairs can work their way into the skin through friction or pressure, often from long periods of sitting, cycling, or tight clothing. Once embedded, the body sees the hair as foreign and mounts an inflammatory response. The result is a tender lump or sinus tract that can become infected and fill with pus.
In some people, this happens once and never returns. In others, the cycle repeats, leading to chronic inflammation and recurring infections. While lifestyle factors certainly play a role, such as sitting for extended periods, the question has always lingered: why are some people more susceptible?
The genetics of hair and why it matters
The UK Biobank study, led by researchers from Oxford Population Health, examined genetic data from hundreds of thousands of patients and identified that certain genes related to hair growth and patterning were more common in people who had developed pilonidal disease.
One gene, LGR5, stood out. This gene is involved in regulating hair follicle development. People with variations in this gene appear to grow thicker or more inwardly curving hair around the lower back and sacral area, which may increase the chance of hair becoming trapped under the skin. The shape, direction, and resilience of the hair likely all play a part in whether it embeds itself and triggers the immune system.
What makes this study so useful is that it provides a biological explanation for what has long been observed anecdotally – that pilonidal disease tends to affect certain body types more than others, often with no clear behavioural cause.
What this means for diagnosis and prevention
At present, there’s no genetic test for pilonidal disease, and this research isn’t suggesting one is imminent. However, this new discovery could lead to better risk assessments, especially in younger people with a family history of the condition.
At the Warwick Bowel and Hernia Clinic, we often see patients with long running or recurrent cases of pilonidal disease. You can find out more about pilonidal treatment options on our page here > https://bowelandhernia.co.uk/surgical-treatments/pilonidal-surgery/
Surgery remains the most effective option for more severe or recurring cases, and techniques continue to improve with better healing and lower recurrence rates.
If you’re suffering from a persistent or recurrent pilonidal cyst, or if you’d like to find out about the most suitable treatment for you, get in touch to book a consultation with Mr Michael Stellakis.
