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Other common
name(s): Australian tea tree oil, melaleuca oil
Scientific/medical
name(s): Melaleuca
alternifolia
Description
Tea tree oil is a concentrated plant oil from the leaves of a
tree native to Australian coastal areas. The tree is known as Melaleuca alternifolia
(or tea tree) and is a member of the myrtle family. The oil is
distilled into the air through a steam process and used on the skin as
an herbal remedy.
Overview
Tea tree oil has been used in Australia for many years to
treat skin infections. It holds some potential as a treatment for
bacterial and fungal infections of the skin and nails. Available
scientific evidence does not support claims that it boosts the immune
system. Tea tree oil is toxic when swallowed and it should never be
taken internally.
How is it promoted for use?
Proponents believe tea tree oil is an antiseptic and use it to
fight germs. It has been used to treat cuts, minor burns, athlete's
foot, and insect bites. Some claim it can treat bacterial and fungal
skin infections, wound infections, gum infections, acne, head lice,
eczema, vaginal yeast infections, colds, pneumonia, and other
respiratory illnesses.
Although no one claims tea tree oil can prevent or treat
cancer, some proponents claim the oil can boost the immune system. Some
herbalists claim that tea tree oil can be used as a "lymphatic
recharge" for a "sluggish" lymphatic system. Available scientific
evidence does not support these claims.
Household cleaners that contain tea tree oil have also been
promoted as alternatives to products that contain cancer-causing
chemicals, such as formaldehyde.
What does it involve?
Tea tree oil can be dissolved in water or used at full
strength. It is also available in the form of ointments, creams,
lotions, and soap. Tea tree oil is often sold in dark glass bottles to
prevent light from affecting its potency. When used to treat infections
and skin conditions, the oil can be applied directly to the skin in
full strength or diluted form using cotton swabs. The oil can also be
found in deodorants, shampoos, soaps, antiseptic first-aid creams,
cosmetics, and household cleaning products.
Tea tree oil should never be taken internally. For colds and
other respiratory illnesses, the oil is added to a vaporizer so that
the mist can be inhaled. Drops of the oil can be added to bath water.
The oil is sometimes mixed in water as a mouthwash.
What is the history behind it?
The aborigines of Australia were the first to discover the
healing properties of tea tree oil thousands of years ago. They treated
cuts, burns, and skin infections by crushing the leaves of the tree and
applying them to cuts and injuries. In the 1770s, the British explorer
Captain Cook observed the native Australians brewing tea from the
leaves. He then brewed tea of his own to give to his crew to prevent
scurvy. He coined the name tea tree.
In the 1920s, Australian physicians began to use the oil to
clean wounds and prevent infections after surgery. They believed it to
be more effective than carbolic acid, the antiseptic most used at that
time. Average Australians then began to use the oil as a household
remedy for skin conditions and fungus infections. During World War II,
tea tree oil was included in the first-aid kits given to all Australian
soldiers and sailors.
After the discovery of penicillin and other antibiotics in the
late 1940s, tea tree oil went out of favor as an antiseptic until the
1980s, when it was discovered that some bacteria were resistant to
certain antibiotics, such as methicillin and vancomycin. Today, there
is renewed interest in tea tree oil as an alternative to these
antibiotics for skin infections.
What is the evidence?
Recent laboratory experiments suggest that tea tree oil holds
promise as an antiseptic when used on the skin to kill germs, including
those that are resistant to methicillin, vancomycin, and other
antibiotics. Other laboratory studies suggest that tea tree oil might
be helpful against scabies (skin mites) and some types of fungus. A
laboratory study published in 2006 showed that tea tree oil can kill
yeasts that cause mouth infections of cancer patients with weakened
immune systems. However, the safety and effectiveness of tea tree oil
has not been tested in clinical studies of cancer patients with mouth
infections, and the fact that tea tree oil is toxic when swallowed
seems likely to limit its use in mouth infections. Even though
laboratory studies may show promise, further studies are needed to find
out whether the results apply to humans.
A few human studies have been done on tea tree oil’s
effectiveness in treating various conditions. In studies to determine
whether tea tree oil helped fungal toenail infections, it compared well
to clotrimazole cream, an older treatment. However, the testing
procedure was scientifically somewhat weak. Tests to find out whether
tea tree oil helped prevent cold sores showed no benefit, but the tests
also had some design flaws that could have affected the results. Tea
tree oil has also been tested to see whether it helped mild acne. It
was compared to benzoyl peroxide for 3 months, and both groups showed
similar improvement by the end of the study. Tests to see whether it
cured athlete’s foot showed mixed results. Despite years of
use, available clinical evidence does not support the effectiveness of
tea tree oil for treating skin problems and infections in humans.
Are there any possible problems or
complications?
This substance
may not have been thoroughly tested to find out how it interacts with
medicines, foods, herbs, or supplements. Even though some reports of
interactions and harmful effects may be published, full studies of
interactions and effects are not often available. Because of these
limitations, any information on ill effects and interactions below
should be considered incomplete.
In rare cases, allergic reactions (such as rashes) to tea tree
oil can occur. The rashes may be mild and itchy, but severe blistering
has been reported as well. The rashes usually improve when the person
stops using the oil. Serious allergic reactions are
possible—one medical report described a man who had immediate
dizziness and swelling in his throat when tea tree oil was applied to
his skin. People who are allergic to other members of the myrtle family
(Myrtaceae),
such as eucalyptus, guava, clove, or allspice, may be more likely to
have an allergic reaction. Those who are sensitive to pine or
turpentine may also react to tea tree oil because of chemical
similarities between the plants. As tea tree oil ages, it breaks down
into substances that are more likely to cause reactions. Using fresher
products that have not been exposed to air, light, and heat may cause
fewer problems with allergies.
Full strength tea tree oil may cause skin irritation even in
people who are not allergic to the oil. These people may have less of a
problem with more diluted oils. Some tea tree oil preparations contain
other ingredients as well, some of which may cause irritation, allergic
reaction, or rash on their own.
There is some evidence that the oil should not be used on
burns. Tea tree oil is not recommended for children. Women who are
pregnant or breast-feeding should not use this oil.
Tea tree oil is toxic when swallowed. It has been reported to
cause drowsiness, confusion, hallucinations, coma, unsteadiness,
weakness, vomiting, diarrhea, stomach upset, blood cell abnormalities,
and severe rashes. It should be kept away from pets and children.
Relying on this type of treatment alone and avoiding or delaying
conventional medical care for cancer may have serious health
consequences.
Additional Resources
More information from your American Cancer
Society
The following information on complementary and alternative
therapies may also be helpful to you. These materials may be found on
our Web site (www.cancer.org)
or ordered from our toll-free number (1-800-ACS-2345).
References
Bagg J, Jackson MS, Petrina Sweeney M, Ramage G, Davies AN.
Susceptibility to Melaleuca alternifolia (tea tree) oil of yeasts
isolated from the mouths of patients with advanced cancer. Oral Oncol.
2006;42:487-492.
Carson CF, Ashton L, Dry L, Smith DW, Riley TV. Melaleuca
alternifolia (tea tree) oil gel (6%) for the treatment of recurrent
herpes labialis. J
Antimicrob Chemother. 2001;48:450-451.
Carson CF, Riley TV. Antimicrobial activity of the major
components of the essential oil of Melaleuca alternifolia. J Appl Bacteriol.
1995;78:264-269.
Faoagali J, George N, Leditschke JF. Does tea tree oil have a
place in the topical treatment of burns? Burns.
1997;23:349-351.
Fetrow CW, Avila JR. Professional's
Handbook of Complementary & Alternative Medicines.
Philadelphia, PA: Lippincott Williams & Wilkins; 2004.
Gruenwald J. PDR
for Herbal Medicines. 3rd ed. Montvale, NJ: Thomson PDR;
2004.
Hammer KA, Carson, CF, Riley TV. In vitro activity of
Melaleuca alternifolia (tea tree) oil against dermatophytes and other
filamentous fungi. J
Antimicrob Chemother. 2002;50:195-199.
Hausen BM, Reichling J, Harkenthal M. Degradation products of
monoterpenes are the sensitizing agents in tea tree oil. Am J Contact Dermat.
1999;10:68-77.
Khanna M, Qasem K, Sasseville D. Allergic contact dermatitis
to tea tree oil with erythema multiforme-like id reaction. Am J Contact Dermat.
2000;11:238-242.
Mozelsio NB, Harris KE, McGrath KG, Grammer LC. Immediate
systemic hypersensitivity reaction associated with topical application
of Australian tea tree oil. Allergy
Asthma Proc. 2003;24:73-75.
Rubel DM, Freeman S, Southwell IA. Tea tree allergy: what is
the offending agent? Report of three cases of tea tree allergy and
review of the literature. Australas
J Dermatol. 1998;39:244-247.
Tea tree oil. Drug Digest Web site.
http://www.drugdigest.org/DD/DVH/HerbsWho/0,3923,551982|Tea+Tree+Oil,00.html.
Accessed June 6, 2008.
Tea tree oil. Memorial Sloan-Kettering Cancer Center Web site.
http://www.mskcc.org/mskcc/html/69396.cfm. Updated August 6, 2007.
Accessed June 6, 2008.
Walton SF, McKinnon M, Pizzutto S, Dougall A, Williams E,
Currie BJ. Acaricidal activity of Melaleuca alternifolia (tea tree)
oil: in vitro sensitivity of sarcoptes scabiei var hominis to
terpinen-4-ol. Arch
Dermatol. 2004;140:563-566.
Note: This information may not cover
all possible claims, uses, actions, precautions, side effects or
interactions. It is not intended as medical advice, and should not be
relied upon as a substitute for consultation with your doctor, who is
familiar with your medical situation.
Last Medical Review: 11/01/2008
Last Revised: 11/01/2008
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