MCV has not been successfully cultured, hampering in vitro studies. A few reports of antiviral activity of TTO have been reported.43-45 Tea tree oil added at non-cytotoxic concentrations (0.003%) to African Green Monkey Kidney (RC-37) cell cultures inhibited propagation of Herpes Simplex Virus (HSV-I) by over 98% in a viral plaque reduction assay,43 demonstrating strong inhibition of a complex enveloped virus in vitro. The authors conclude that free virus appeared to be very sensitive to the antiviral effects of TTO. The reduced infectivity of virus after incubation with TTO suggests that TTO may bind to virion envelope structures or may mask viral components necessary for adsorption or entry into host cells, but the exact mechanism is not known. It is unclear if these findings in culture relate in part or at all to the mechanism of action in this present clinical study. A clinical report of topical TTO against common hand warts caused by HPV has also appeared.45
The speed of action of TTO-I and a lack of generalized inflammation associated with its use suggested that the mixture was not acting as a generalized immune stimulant (e.g., Aldara), but rather may act more directly to inhibit viral propagation in some manner as discussed above. Furthermore, the apparent lack of a generalized toxicity to the skin in this study suggests that TTO-I was not acting by means of non-specific tissue destruction. The skin permeation effects of TTO are fairly limited,48,49 however, there are components with significant lipophillicity.46 The mechanism underlying the synergy between TTO and iodine demonstrated in this study is unclear. It may relate to enhanced penetration of iodine into superficial layers of skin by the TTO or some other as yet unidentified interaction.
The results of this study suggest that tea tree oil and organically bound iodine in combination are efficacious and safe in the topical treatment of MC in children.
This work was supported by intramural funding from the Center for Biomedical Research, Inc. Boise, ID. The authors gratefully acknowledge the generous help and support of Dr. Richard Olson of the Boise VA Medical Center.
The authors have no relevant conflicts of interest to disclose.
- Bateman F. Molluscum contagiosum. In: Shelley WB, Crissey JT, eds. Classics in Dermatology.Springfield IL; Charles C Thomas, 1953;20.
- Molluscum Contagiosum. eMedicineHealth [online]. Available at: http://www.emedicinehealth.com/molluscum_contagiosum/article_em.htm.
- Husar K, Skerlev M. Molluscum contagiosum from infancy to maturity. Clin Dermatol. 2002;20:170-172.
- Gottlieb SL, Muskows PL. Molluscum Contagiosum. Int J Derm. 1994;33:453-461.
- Baldwin HE. STD update: screening and therapeutic options. Int
J Fertil Womens Med. 2001;46:79-88.
- Becker TM, Blout JH, Douglas J, Judson FM. Trends in molluscum contagiosum in the U.S. 1966-93. Sex Transm Dis 1996;13:88-92.
- Schwartz JJ, Muskowski PL. Molluscum contagiosum in patients with human immunodeficiency virus infection. J Am Acad Derm. 1992;27:583-585.
- Senkevich TG, Koonin EV, Bugert JJ, Darai G, Moss B. The genome of molluscum contagiosum virus: analysis and comparison with other poxviruses. Virology. 1997;1233:9-42.
- Dohil P, Lin J, Lee A, Lucky A. Paller L, Eichenfield LF. The epidemiology of molluscum contagiosum in children. J Amer Acad Derm. 2006;54:47-54.
- Danzall, BG, Witson GR Molluscu contagiosum in a red kangaroo. Aust J Derm. 1974;15:115-117.
- Van Resburg IB, Collett MG, Ronen N, Gerdes T. Molluscunm contatiosum in a horse. J S Afr Vet Assoc. 1991;62:72-74.
- Habif TP. Clinical Dermatology: A Color Guide to Diagnosis and Therapy. 2nd Ed., St. Louis: CV Mosby Co, 1990;248-249.
- Moss B, Shisler JL, Xiang Y, Senkevich TG. Immune-defense molecules of molluscum contagiosum virus, a human poxvirus. Trends Microbiol. 2000;10:473-477.
- Diven DG. Recent advances in moll cont virus res. Arch Virol Suppl. 1997;13:35-47.
- Silverberg NB, Sidbury R, Mancini AJ. Childhood molluscum contagiosum: experience with cantharidin therapy in 300 patients. J Am Acad Dermatol. 2000;43:503-507.
- Romiti R, Ribeiro AP, Romiti N. Evaluation of the effectiveness of 5% potassium hydroxide for the treatment of molluscum contagiosum. Pediatr Dermatol. 2000;17:495-498.
- Hanson D, Diven DG. Molluscum Contagiosum. Dermatol Online J. 2003;9:2-13.
- Berman P, Poochareon VN, Villa AM. Novel dermatologic uses of the immune response modifier imiquimod 5% cream. Skin Therapy Lett. 2002;7:1-6.
- Smith KJ, Skelton H. Molluscum contagiosum: recent advances in pathogenic mechanisms, and new therapies. Am J Clin Dermatol. 2002;3:35-45.
- Burke BE, Baillie JE, Olson RD. Essential oil of Australian lemon myrtle (Backhousia citriodora) in the treatment of molluscum contagiosum in children. Biomed Pharmaco. 2004;58:245-247.
- Hayes AJ, Markovic B. Toxicity of Australian essential oil of Backhousia citriodora (Lemon myrtle). Part 1. Antimicrobial activity and in vitro cytotoxicity Food Chem Toxicol. 2002;40:535-543.
- Carson CF, Hammer KA, Riley TV. Melaleuca alternifolia (Tea Tree) oil: a review of antimicrobial and other medicinal properties. Clin Microbiol Rev. 2006;1:50-62.
- Penfold AR, Grant R. The germicidal values of some Australian essential oils and their pure consituents. J Proc Royal Soc NSW. 1925;59:346-350.
- Carson CF, Riley TV. Antimicrobial activity of the major components of the essential oil of Melaleuca alternifolia. J Appl Bacteriol. 1995;78:264-269.