Lifestyle may prompt cyst development

Last year I had a cyst near my tailbone which was drained by my GP. It still gets a bit uncomfortable at times, a little swollen every few months. I've been reading up on pilonidal cysts and think I may have had one. What is the next step in treating these? - MK

Pilonidal is a vexing disease. Affected patients get painful cysts under the skin of the natal cleft (the fold between the buttocks) overlying their sacrum. These can get infected, forming abscesses, and can recur even after incision and drainage, or lie dormant for years. And they have a propensity to grow in size, sometimes forming large cavernous tracts within the skin which can fill with pus and hair. At their worst, they can cause serious infection and require significant surgeries to excise and correct.

Besides being persistent, pilonidal disease has been poorly understood medically. Pathologists found that the cysts were lined with epidermis (outer skin) tissue and assumed  an embryological defect was responsible.  The fact they ran in families also supported a genetic or developmental cause. It was assumed that  people were just born with them and would develop symptoms sooner or later.

Doctors now think that the cysts are inflammatory reactions to ingrown hairs working their way into the skin. This rather simple explanation seems plausible as the disease predominantly affects hairy individuals, the obese, and those who spend large amounts of time sitting. This also gives us some ideas of which lifestyle modifications might work to prevent pilonidal disease, namely depilation, weight loss and physical activity.

Given the range of severity, no simple solution fits everyone. One important first step is having your doctor make sure that your problem is not related to anal or rectal disease. Your doctor will then figure out whether the disease has burrowed beneath your skin and whether there is active infection.

Infection would be treated by incision and drainage and possibly antibiotics. But if there is a rabbit warren of sinus tracts you'll eventually need referral to a surgeon for, hopefully, definitive treatment because of  the increased risk of recurrence and other complications.

Gary Payinda MD is an emergency medicine consultant in Whangarei.

If you have  a science, health topic or question you'd like addressed, email: drpayinda@gmail.com

(This column provides general information and is not a substitute for the medical advice of your personal doctor.)