Results Summary

What was the research about?

Pilonidal disease is a health problem that causes a skin infection near the buttocks due to ingrown hairs. The disease usually affects teens and young adults. It can cause painful, bad-smelling wounds, which may embarrass patients and keep them from going to school or work.

Doctors can treat the infection with medicine and surgery. To keep the infection from returning, patients must keep the area clean and shave or use hair removal creams. Laser treatments are another option and can remove hair long term. Questions remain about whether laser hair removal works better than shaving or creams alone to prevent repeat infections.

In this study, the research team compared two approaches to prevent repeat infection in patients with pilonidal disease:

  • Shaving or hair removal creams alone
  • Shaving or hair removal creams plus laser hair removal

What were the results?

After one year, 34 percent of patients who used shaving or creams alone had the infection return compared with 10 percent of patients who also had laser hair removal.

The two types of treatment didn’t differ in:

  • Days that a patient and caregiver couldn’t take part in their normal activities
  • Quality of life
  • Satisfaction with health care
  • Attitude toward pilonidal disease 
  • Feelings of stigma, or judgment from other people
  • Serious health problems related to pilonidal disease
  • Doctor visits or surgeries for pilonidal disease
  • How closely patients followed the treatment plan

Who was in the study?

The study included 230 patients ages 11–21 with pilonidal disease. Of patients, 75 percent were White, 11 percent were Black, 3 percent were Asian, 2 percent were Hispanic or Latino, 1 percent were American Indian, 1 percent were Pacific Islander, 5 percent were more than one race, and 2 percent didn’t report race or ethnicity. The average age was 17, and 56 percent were male. All received care at one hospital in Ohio.

What did the research team do?

The research team assigned patients by chance to receive laser hair removal or not. All patients received a six-month supply of razors or hair removal cream. They also received information about how to shave and use creams to prevent repeat infection. Patients who had laser hair removal had five treatments spaced four to six weeks apart. They shaved or used cream as needed.

At the start of the study and one year later, the research team looked at health records. Patients completed surveys about their experiences.

Patients, caregivers, doctors, and members of advocacy groups provided input during the study.

What were the limits of the study?

Most patients in the study were White and non-Hispanic. About 27 percent of patients who had laser hair removal and 10 percent who used shaving and creams alone didn’t complete all surveys. Results may have differed with patients of different backgrounds or if more patients completed surveys.

Future research could test laser hair removal with more patients and among more diverse patients.

How can people use the results?

Patients with pilonidal disease and their doctors can use the results when considering treatments to keep infection from returning.

Final Research Report

This project's final research report is expected to be available by November 2024.

Peer-Review Summary

Peer review of PCORI-funded research helps make sure the report presents complete, balanced, and useful information about the research. It also assesses how the project addressed PCORI’s Methodology Standards. During peer review, experts read a draft report of the research and provide comments about the report. These experts may include a scientist focused on the research topic, a specialist in research methods, a patient or caregiver, and a healthcare professional. These reviewers cannot have conflicts of interest with the study.

The peer reviewers point out where the draft report may need revision. For example, they may suggest ways to improve descriptions of the conduct of the study or to clarify the connection between results and conclusions. Sometimes, awardees revise their draft reports twice or more to address all of the reviewers’ comments. 

Peer reviewers commented and the researchers made changes or provided responses. Those comments and responses included the following:

  • The reviewers noted that the conclusions of this study regarding generalizability needed to be tempered given the differential patient drop out between study arms and evidence that effectiveness of treatment may differ across racial and ethnic groups. The researchers responded to the concern about differential patient drop out by saying that they did not believe more study participants were lost to follow-up in the laser treatment arm because of treatment intolerance since follow-up rates were the same in the treatment and comparator groups until six months, when the laser therapy was completed. The researchers instead stated that participants in the treatment group were less likely to complete follow-up measures after this point if they did not have recurrence of pilonidal disease, whereas participants in the comparator group stayed involved in the study because they were offered laser hair removal at no cost once the study was completed.
  • The reviewers also commented on the much higher number of participants who were randomized to but did not receive laser treatment (n = 20) compared to participants randomized to but did not receive standard care (n = 2). The reviewers were concerned that this indicated greater concern about receiving laser treatment than the researchers noted. The researchers explained instead that this difference was an artifact of the study flow, since standard care started for all participants on the day they agreed to be in the study while laser hair removal was scheduled for one to four weeks later. In addition, due to the COVID-19 pandemic the researchers needed to delay the start of laser treatment for a number of participants. By the time they were able to continue, 15 participants in the laser treatment arm had dropped out.
  • The reviewers asked the researchers to consider revising some of their statements related to race given that this is a social construct rather than a biological difference such as skin color. The reviewers also pointed out that the researchers referred to “both” sexes, which was exclusive of other sexual identities, and used the term “compliance” rather than “adherence,” the latter being more patient centered. The researchers replaced occurrences of “compliance” with “adherence” and added information about how laser treatment and treatment effects differed by skin type.

Conflict of Interest Disclosures

Project Information

Peter C. Minneci, MD, MHSc
Cory N. Criss, MD
The Research Institute at Nationwide Children's Hospital
$1,266,752
Randomized Controlled Trial of Laser Hair Depilation in Adolescents with Pilonidal Disease

Key Dates

November 2017
November 2023
2017
2024

Study Registration Information

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Intervention Strategy Intervention Strategies PCORI funds comparative clinical effectiveness research (CER) studies that compare two or more options or approaches to health care, or that compare different ways of delivering or receiving care. View Glossary
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Last updated: March 14, 2024