The Efficacy of Onion Extract and Contractubex on the Prevention or Treatment of Scars: A Systematic Review

Objective:
We aimed to review the literature regarding use of Onion Extract (OE) in the prevention and treatment of scars in patients.

Background:
There is currently no consensus regarding the gold standard in treatment and prevention of scars. Non-invasive interventions such as silicone gel or immune modulators are popular adjuvant treatments due to ease of application and nature.1 Several commercial formulations of OE such as Contractubex are available for the prevention of scar formation and promoting scar smoothness.2 OE has been proposed as a scar treatment and prevention modality due to its anti-microbial and anti-inflammatory properties.2 Due to the high demand for scar formation prophylaxis, investigating OE topicals will allow direct clinical application of this therapy. Since the current literature displays mixed OE outcomes, this review aims to analyze the discrepancies and bridge the gap between varying OE conclusions.

Methods:
A systematic search of the literature was done using PubMed, Scopus, and Cochrane for articles published between January 2000 and December 2021 using the following keywords: Contractubex, OE, Hypertrophic, Keloid, Scar. Inclusion criteria were the following: (a) involved Contractubex or OE treatment; and (b) assessed scar prevention and treatment outcomes. Non-English studies, animal studies, in-vitro studies, case reports, case series, reviews, and letters to the editors were excluded. Objective, subjective, and patient reported scar outcomes after treatments, adverse effects were recorded. A meta-analysis could not be executed due to heterogeneity of data and comparison groups.

Results:
A total of 21 articles were included in the final review. Patient and Observer Subjective Assessment Scale (POSAS) and the Vancouver Scar Scale (VSS) were utilized to determine treatment efficacy of OE. 5 studies found a statistically significant improvement in overall scores and individual VSS components in the OE treatment group compared to the silicone groups. Several studies found combined treatment of OE with other topical treatment modalities such as triamcinolone or silicone gel produced a statistically significant improvement in scar symptoms. In this review, the only adverse effects encountered were minimal pruritus, irritation, and erythema, which were tolerable and study participants continued treatment without significant discomfort.

Conclusion:
This review supports OE's potential utility in scar prevention and treatment. The majority of studies examined reported minimal adverse events with OE application and significant benefits in addressing specific scar characteristics. Further research focused on elucidating effectiveness of OE and adjunctive therapy with silicone as compared to corticosteroids are needed. Additional research is also needed to investigate scar outcomes after treatment with OE with larger sample sizes and a follow up period greater than a year.

References:

1. Ojeh, N., Bharatha, A., Gaur, U., & Forde, A. L. (2020). Keloids: Current and emerging therapies. Scars Burn Heal, 6, 2059513120940499. doi:10.1177/2059513120940499

2. Draelos, Z. D., Baumann, L., Fleischer, A. B., Jr., Plaum, S., Avakian, E. V., & Hardas, B. (2012). A new proprietary onion extract gel improves the appearance of new scars: a randomized, controlled, blinded-investigator study. J Clin Aesthet Dermatol, 5(6), 18-24.

Aesthetic

Plastic Surgery 2022