Open Source Apothecary At Home / Skin and wounds

Skin infections: impetigo, cellulitis, fungal and the tea tree question

Tea tree has real trials for acne and fungal infection. Cellulitis and impetigo need antibiotics.

remedy

Skin infections split into those where a topical plant preparation has evidence, and those where antibiotics are needed and a delay causes harm.

Where a plant preparation has evidence:

• Acne. Tea tree oil at 5% has a randomised trial showing effectiveness comparable to 5% benzoyl peroxide, with slower onset and fewer side effects. This is one of the better-supported herbal dermatology findings. Benzoyl peroxide remains the standard first-line topical.
• Athlete's foot and other dermatophyte infections. Tea tree oil has in-vitro activity and small clinical trials. Terbinafine and other topical antifungals have far better cure rates; tea tree is the option for someone who cannot use them.
• Cold sores. Lemon balm (Melissa officinalis) cream has randomised trial evidence for herpes labialis, reducing healing time and symptoms. It is modest, gentle and safe.
• Verrucae, mild seborrhoeic dermatitis, minor fungal nail change: weak evidence, various traditional preparations.

Where antibiotics are needed and a plant preparation is a delay:

• Impetigo — the classic honey-coloured crusted lesions, usually in children. Topical or oral antibiotics depending on extent; it is contagious and it can cause post-streptococcal kidney disease.
• Cellulitis — spreading redness, warmth, pain, often with fever. Needs antibiotics, and a delay is how someone ends up in hospital.
• Any infection with fever, a red streak, or rapidly increasing pain.

The dilution and sensitisation issue. Tea tree oil at full strength is a sensitiser, and repeated neat application causes allergic contact dermatitis. Use it diluted (5% for acne, 10-25% for fungal skin infection) and stop if a rash develops. This is one of the most common plant-related dermatology problems.

The one that is not a herb and matters. Benzoyl peroxide for acne, a topical antifungal for athlete's foot, and sunscreen for prevention — all have better evidence than the herbal options and all are cheap.

What the studies found

Preparation

Acne — tea tree oil

• 5% tea tree oil in a carrier gel, applied to affected areas twice daily
• Comparable to 5% benzoyl peroxide in the trial, with a slower onset (allow 8-12 weeks) and fewer side effects
• Patch test first. Neat tea tree oil sensitises the skin.
• Benzoyl peroxide remains the better-evidenced first-line topical and is cheap

Cold sores — lemon balm

• A 1% lemon balm cream, applied 2-4 times daily from the first tingle
• Trials show reduced healing time and symptoms
• Generally gentle

Athlete's foot — tea tree oil

• 10-25% tea tree oil in a carrier, or a tea tree cream, applied twice daily for 4 weeks
• Topical terbinafine has far better cure rates if available
• Dry the feet thoroughly, especially between the toes; change socks daily; treat the shoes

Minor wounds and grazes

• Irrigation with clean water is the intervention
• Tea tree oil is not for open wounds

What is not a tea tree situation

• Impetigo — honey-coloured crusts, usually in children. Needs antibiotics, and it is contagious.
• Cellulitis — spreading redness with fever. Needs antibiotics urgently.
• A fungal nail infection — topical treatments rarely cure it; oral treatment is a medical decision.

Dilution reference

| Use | Concentration | |---|---| | Acne | 5% | | Fungal skin infection | 10-25% | | Minor irritation | 1-3% | | Neat, on skin | Do not |

Cautions and interactions

• Do not use tea tree oil neat on skin. It is a sensitiser and causes allergic contact dermatitis.
• Do not use tea tree oil on open wounds, burns, or near the eyes.
• Impetigo and cellulitis need antibiotics. A topical plant preparation is a delay.
• Tea tree oil is toxic if swallowed. Keep it away from children.
• Do not use tea tree oil on cats or dogs — it is toxic to them, and pets licking it has caused poisoning.

When this is not a self-care problem — get help

• Spreading redness, a red streak, fever, increasing pain, or an area that is hot and swollen — urgent assessment. Cellulitis can become sepsis.
• Honey-coloured crusted lesions with new lesions spreading, in a child — impetigo, needs treatment, and it is contagious.
• A skin infection in a person with diabetes or immunosuppression — urgent assessment.

Related

• Wounds and grazes
• Acne
• Eczema and atopic dermatitis
• Insect bites and stings

Sources

1. Efficacy and Safety of Melaleuca alternifolia (Tea Tree) Oil for Acne-A Systematic Review and Meta-Analysis. Phytotherapy research : PTR 2026; doi:10.1093/bjd/ljae352 PubMed 42098589
2. Essential oils as topical anti-infective agents: A systematic review and meta-analysis. Complementary therapies in medicine 2019; doi:10.1016/j.ctim.2019.102224 PubMed 31780027
3. Vaginal Cleansing Before Cesarean Delivery: A Systematic Review and Meta-analysis. Obstetrics and gynecology 2017; doi:10.1097/AOG.0000000000002167 PubMed 28796683
4. Complementary therapies for acne vulgaris. The Cochrane database of systematic reviews 2015; doi:10.1002/14651858.CD002086 PubMed 25597924
5. Evaluating efficacy, safety, and innovation in skin care applications of essential oils: a systematic review. Frontiers in medicine 2025; doi:10.1177/1091581819862504 PubMed 40917836
6. Herbal Medicine for Treating Herpes Labialis: A Systematic Review. Journal of integrative and complementary medicine 2025; doi:10.1089/jicm.2025.0131 PubMed 40526027