Tea Tree Oil for Demodex Blepharitis: Promising but Requires Robust Clinical Trials and Enhanced Formulations

A systemic review published in Frontiers in Pharmacology, examines tea tree oil's (TTO) therapeutic efficacy and safety in various clinical applications, including treating Demodex blepharitis. Traditionally, tea tree oil, derived from the Australian tea tree plant Melaleuca alternifolia, has been used for its medicinal properties, but the evidence for its effectiveness has been limited. The review includes randomized controlled trials (RCTs) comparing tea tree oil to control groups in various medical fields, including dentistry, dermatology, infectious disease, ophthalmology, podiatry, and others.

Some key findings from the review include:

1. Tea tree oil mouthwashes with 0.2%–0.5% TTO may help reduce dental plaque accumulation.
2. Gels containing 5% TTO applied to the periodontium may aid in treating periodontitis as an adjunct to scaling and root planing.
3. Tea tree oil can potentially reduce acne lesions and severity, but more evidence is needed.
4. Topical TTO regimens are effective for decolonizing the body from methicillin-resistant Staphylococcus aureus (MRSA), but intra-nasal use may cause mucous membrane irritation.
5. Tea tree oil with added iodine may effectively treat molluscum contagiosum lesions in young children.
6. Tea tree oil-based eyelid wipes may help control Demodex mite infestations, but more research is needed.
7. Safety issues are raised, particularly when TTO is applied topically in concentrations ≥ 25%, which can lead to minor side effects.

However, the review also identifies several limitations, including:

1. Limited reporting of the brand and composition of TTO used in trials affects the reliability of results.
2. Challenges with blinding participants due to the strong aroma of TTO.
3. Some studies lack an assessment of compliance/adherence to the interventions and adverse events.
4. Heterogeneity in TTO-based product formulations can affect efficacy.
5. Concerns about the safety of TTO, particularly in high concentrations, which can cause skin irritation.
6. Researchers referenced three studies to investigate the effectiveness of tea tree oil-based eyelid wipes, washes, or scrubs in managing Demodex mite infestations and related ocular conditions.

In one study, 135 adult subjects with diagnosed demodectic blepharitis compared twice-daily eyelid washes with Blefaroshampoo® (containing 7.5% tea tree oil) to Blepharitis Shampoo without tea tree oil. The study found a significant reduction in Demodex mite count and improvement in ocular symptoms among those using Blefaroshampoo.

In another study, 281 adult subjects with ocular surface discomfort compared twice-daily eyelid scrubs using 10% tea tree oil diluted in mineral oil to saline eyelid scrubs. The research demonstrated that the tea tree oil eyelid scrubs were more effective in reducing Demodex mite counts, particularly in participants who used them more than 10 times weekly. Moreover, patient-reported ocular discomfort significantly decreased with the tea tree oil scrub.

The third study referenced by researchers found the efficacy of BlephaDex™ eyelid wipes containing tea tree oil in 20 subjects aged 45 years and older, comparing them to a no-treatment control group. The study found that the use of BlephaDex™ wipes resulted in a significant reduction in Demodex mite count. However, the study had a smaller sample size than the other two trials.

These studies suggest that tea tree oil-based eyelid products may effectively manage Demodex mites and associated ocular symptoms. Still, the tolerability and safety of different commercial products require careful consideration.

While TTO shows promise in various therapeutic applications, the review highlights the need for further well-designed clinical trials to confirm its benefits and assess safety. "Novel formulations should also be considered to enhance localized delivery of active components of tea tree oil. Further, it is critical to assess safety of tea tree oil treatments to better understand the risks to patients and consumers of these products," said researchers.

Reference

Kairey L, Agnew T, Esther Joy Bowles, Barkla BJ, Wardle J, Romy Lauche. Efficacy and safety of Melaleuca alternifolia (tea tree) oil for human health—A systematic review of randomized controlled trials. Frontiers in Pharmacology. 2023;14. doi:https://doi.org/10.3389/fphar.2023.1116077