Last updated on April 20, 2014 at 8:28 EDT

Pilonidal Cyst Comes Back

September 18, 2005

Q: For as long as I can remember, I’ve had a cyst on the end of my tailbone. Then, a few years ago, it started acting up and I went to a doctor, who referred me to a surgeon. The surgeon operated on it, but after a year it has returned.

Now the surgeon tells me that these so-called pilonidal cysts often do recur, and he can’t guarantee that it won’t happen again. I’m only 30 years old. Do I have to look forward to this happening the rest of my life?

— I.L., Rawlings, Md.

A: A pilonidal cyst is very different from other types of cysts that everyone has had from time to time. These form as dead skin collects or infections take place inside a pilonidal sinus. This is the name given to any localized area under the skin that contains hairs. The most common location for a pilonidal cyst is the skin in the area of the tailbone.

The cysts often occur in women between puberty and age 40. People who are obese or those with thick body hair have an increased risk of pilonidal cysts.

The cyst may not cause any symptoms unless it becomes infected. Trauma or injury to the area may cause the cyst to become tender and painful, to form an abscess, and possibly to drain. Trauma increases the risk of bacterial infection in a pilonidal sinus.

Treatment is straightforward, beginning with antibiotics if the area is infected, followed by surgical removal. Many surgical procedures are available, and there is little evidence that one approach works much better than another. Simple incision and scraping it out is commonly used. Benefits and risks of any recommended surgical procedure should be discussed with the surgeon.

These cysts often return after surgery, and the recommended response is to do the surgery again. Unfortunately, the medical research does not indicate which surgical approach is best the second time around.

A recent study done in Europe, reported in the November 2004 issue of the medical journal Diseases of the Colon and Rectum, showed that crystallized phenol was very effective in treating pilonidal cysts.

This chemical was applied topically to the area of the cyst two or three times. The research found that it worked 95 percent of the time, and in only 5 percent of cases did a cyst recur over two years. This appears to be an easy and effective treatment, but it may be years before it is commonly available.

Since you have already had surgery, it very likely that you have a pilonidal cyst. But prior to surgery it can be confused with another problem called hidradenitis suppurativa.

This is a chronic skin condition in which there is inflammation in and around certain types of hair follicles. However, the hair follicles most affected by hidradenitis are located in the groin, armpit and around the nipples.

The most common symptoms are painful, tender, firm, lumpy lesions under the arms. They may open and drain pus spontaneously. Nodules recur several times yearly, but in severe cases there is a constant succession of new lesions.

There is really no great medical treatment for hidradenitis. It usually heals slowly, with or without treatment, over 10 to 30 days.