The goal of this randomized clinical trial is to establish the efficacy of 'pit picking with laser therapy' versus 'pit picking alone' on both short and long-term outcomes in patients of 12 years and older with primary pilonidal sinus disease.

The main questions it aims to answer are:

• The overall success rate of treatment which is defined as: closure of all pits at 12 months of follow-up.
• Secondary endpoints: succes rat eof treatment during long-term follow-up, wound closure time, pain scores, complication rate, work rehabilitation, time to return to daily activities, quality of life, persisting complaints, patient satisfaction, costs and the need for secondary or revision surgery.

Participants will allocated to pit picking alone or combined with lasertherapy.

The extra burden for participating patients is expected to be minimal to moderate. Participants will have two extra hospital visits in casethey are enrolled in our study: 6 and 12 months after enrolment. Postoperatively the normal scheme of follow up appointments wil be used: 2 and 6 weeks after treatment at the outpatient clinic of the treating surgeon. A telephone appointment with the researcher will be scheduled 4 weeks after treatment. Patients are asked to complete questionnaires at various time points, which will be sentto them by email and will take approximately 5-10 minutes each time. The content includes general and disease specific Quality of Life (QoL) questionnaires. The investigators do not expect any extra adverse reactions or events in respect to participation in the study because both procedures are considered standard of care in the participating clinics. However, because both interventions are surgical procedures a small percentage of adverse events or postoperative complications can be expected.

Inclusion Criteria:

• All patients aged 12 years and older who present with primary pilonidal sinus disease; Type 1b and 3 of the Dutch staging system
• Obtained written informed consent by the patient and/or legal representative/parent
• Sufficient understanding of the Dutch written language (reading and writing)
• Eligible for questionnaires sent by e-mail

Exclusion Criteria:

• Asymptomatic (Type 1a), recurrent (Type 4; except those patients who only have had drainage of their abscess and no other surgical treatment), or chronic wounds (hypergranulating) after PSD surgery (Type 5) of the Dutch staging system
• Patients with known underlying or concomitant medical conditions that may interfere with normal wound healing (e.g. systemic skin and connective tissue diseases, any kind of congenital defect of metabolism including insulin-dependent diabetes mellitus, Cushing syndrome or disease, scurvy, chronic hypothyroidism, congenital or acquired immunosuppressive condition, chronic renal failure, or chronic hepatic dysfunction (Child-Pugh class B or C), severe malnutrition, or other concomitant illness which, in the opinion of the investigator, has the potential to significantly delay wound healing)
• Severe drug abuse (and therefore protocol deviation can be expected)
• Patients expected not to comply with the study protocol (including patients with severe cognitive dysfunction/impairment and severe psychiatric disorders)
• Patients with insufficient knowledge of the Dutch written language who are thus unable to answer the questionnaires
• Patients that are unable or not willing to give full informed consent

On reasonable request.

Only the outcome assessor is blinded.