The use of local liquid phenol for pilonidal sinus disease was first introduced by Maurica and Greenwood in 1964. Phenol, also known as carbolic acid, has been proven to be an effective sclerosing agent for treating pilonidal sinus diseas. Its antiseptic and anesthetic qualities make it suitable for application in awake patients under local anesthesia. The treatment of pilonidal sinus diseas in children with crystallized phenol was first published by Ateş et al in 2018. However, the treatment involving only crystallized phenol can require numerous sessions, potentially extending the duration of the treatment. IIn this study, the investigators, investigated whether the application of platelet-rich plasma following crystallized phenol treatment could accelerate the healing process and reach better outcomes. This study evaluates the efficacy of PRP as a treatment modality for pilonidal sinus disease in pediatric patients.

Upon their arrival at our pilonidal care clinic, patients commenced a regimen of manual shaving of the gluteal cleft either weekly or bi-weekly. Laser epilation therapy was initiated at the earliest opportunity, conducted every 6 to 8 weeks, aiming for a hair reduction of over 90%. For patients presenting with a pilonidal abscess, an initial procedure of incision and drainage was performed, followed by antibiotic therapy. In the outpatient clinic, patients were placed in a prone position, and the area was sterilized with a povidone-iodine solution.

Anaesthesia local: The skin and subcutaneous tissues surrounding the PSD area, including the sinus openings, receive local anesthesia with 5 ml of lidocaine (20 mg/ml) mixed with epinephrine (0.0125 mg/ml).

Zone keeps clean: The area surrounding the PSD is thoroughly disinfected with povidone-iodine solution, covering a minimum area of 20 square centimeters to ensure adequate local disinfection.

Irrigation with isotonic solution: The wound is washed with sterile isotonic solution.

Zero hair (removing hair and curettage): For sinuses measuring ≤ 3 mm in diameter, dilation is performed using a mosquito clamp (BH-109, Aesculap®, Center Valley, PA, USA). Hair within the sinus is removed. After the complete removal of hair from the area, the granulation tissue is then excised through curettage.

Ointment application around the wound: To prevent skin necrosis and burns, a 0.2% nitrofurazone (Furacin® Eczacıbası İlaç San, Istanbul, Turkey) ointment is meticulously applied around the pilonidal sinus area immediately before the CP application, ensuring a protective barrier and enhancing skin safety.

Gravel-like crystallized phenol application: In this instance, the phenol applied is not in liquid form; rather, it is in a solid, gravel-like form. CP (BotaFarma İlaç Medikal İtriyat Kimya San. Tic. Ltd. Şti, Ankara, Turkey) is carefully administered into the cavity via the orifice, with the precise amount required just sufficient to fill the cavity without causing any overflow. This step necessitates meticulous attention to ensure the correct dosage and prevent any potential spillage. Typically, for an average pediatric patient and the size of the defect encountered, an amount ranging from 4 to 6 grams of phenol is deemed adequate to effectively treat the area while minimizing risk.

Local re-disinfection prior to PRP injection: Up to this point, all procedures are identical for both groups. However, the following steps and any subsequent applications are exclusively for Group 2. The area around the pilonidal sinus should be thoroughly disinfected again with povidone-iodine (care should be taken to prevent povidone-iodine from entering the sinus itself). This step is critical because, following this phase, a PRP injection will be administered into the tissue, necessitating that the skin is properly disinfected to minimize the risk of infection.

Undergo PRP injection: In Group 2, patients received a PRP injection during the same session as the CP application. The amount of PRP injected-approximately 1-2 ml, depending on the size of the pilonidal sinus-was administered around the edges and surrounding area of the wound.

Inclusion Criteria:

The study will be included patients with pilonidal sinus disease aged between 0 to 18 years.

Exclusion Criteria:

Patients who had undergone prior pilonidal sinus disease surgery or had anomalies in the sacrococcygeal region will be excluded from the study. Additionally, patients who will decline to participate in the study or will be failed to attend post-procedural outpatient follow-ups will also be excluded.