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Successful topical treatment of hand warts in a paediatric patient with tea tree oil (Melaleuca alternifolia)
ARTICLE IN PRESS Complementary Therapies in Clinical Practice (2008) 14, 225–227
www.elsevierhealth.com/journals/ctnm
Successful topical treatment of hand warts in a paediatric patient with tea tree oil (Melaleuca alternifolia) B. Cherie Millar, John E. Moore Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Lisburn Road, Belfast, Northern Ireland BT9 7AD, UK
KEYWORDS Warts; Tea tree oil; TTO; Essential oils; Human papilloma virus; HPV; Dermatology
Summary Tea tree oil (TTO) (Melaleuca alternifolia) has been used recently as an effective topical application for the treatment of skin infections due to a variety of aetiological microbial agents, including mainly bacterial infections. We detail the first report in the peer-reviewed literature of the successful treatment with TTO of a paediatric patient with warts on her right middle finger. TTO was applied topically once daily to the lesions for 12 days, with a successful outcome, including complete re-epithelization of the infected areas. The case highlights the potential use of TTO in the treatment of common warts due to human papilloma virus. & 2008 Elsevier Ltd. All rights reserved.
Case study A seven-year-old girl presented with six warts on the skin associated with the distal phalanges of her right middle finger. On examination, her finger appeared distorted due to the presence of the warts, which were located on both the dorsal and aspect of the finger, as well as on the tip of the finger. More recently, she complained of growing discomfort associated with the presence of the warts in writing and playing the piano. There were no lesions elsewhere on her body. The patient had a history of recurrent warts at the same anatomical Corresponding author. Tel.: +44 28 9026 3554;
fax: +44 28 9026 3991. E-mail address: [email protected] (J.E. Moore).
location, which had been treated topically with salicylic acid (12% w/w) and lactic acid (4% w/w) for several weeks, which resulted in a temporary removal of the warts, before they recurred in greater numbers. Given this history, it was decided on this occasion to treat the warts with topical tea tree oil (TTO) (Melaleuca alternifolia). One hundred percent TTO (Holland and Barrett Ltd., Nuneaton, Warwickshire, UK) was applied with sterile cotton wool swabs to each of the lesions, each evening after bathing and prior to sleep. After 5 days, all warts had considerably reduced in size, with little deformity to the digit and after a further 7 days, there was no evidence of the presence of warts, at which point, treatment was discontinued. There has been no recurrence of the lesions to date.
1744-3881/$ - see front matter & 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.ctcp.2008.05.003
ARTICLE IN PRESS 226
B.C. Millar, J.E. Moore
In recent years, TTO has become a widely used treatment for a wide variety of conditions, ranging from the treatment of head lice to ulcers and other infectious diseases.1 Although this anecdotal evidence of its efficacy is widespread and abundant amongst practitioners of complementary medicine,
Table 1
there has only been a limited number of published clinical studies, examining the efficacy of TTO against bacterial, fungal and protozoal infections. In particular, there have only been three published reports on the efficacy of TTO solely against herpes simplex virus (HSV),2–4 and there have been no
Summary of reports on the antiviral properties of tea tree oil.
Viral agent
Study type
Main findings of study with respect to TTO activity
Ref.
Herpes simplex virus (HSV) (Types 1 and II)
In vitro plaque reduction assay
2
Herpes simplex virus (HSV Type 1)
In vitro plaque reduction assay
Herpes simplex virus (HSV Type 1)
Randomized control trial (RCT)/ investigator blinded
Cytotoxicity of TTO was evaluated in a standard neutral red dye uptake assay. Toxicity of TTO was moderate for RC-37 cells and approached 50% (TC50) at concentrations of 0.006%. Antiviral activity of TTO against herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) was tested in vitro on RC-37 cells using a plaque reduction assay. The 50% inhibitory concentration (IC50) of TTO for herpes simplex virus plaque formation was 0.0009% and 0.0008% for HSV-1 and HSV-2, respectively, and TTO exhibited high levels of virucidal activity against HSV-1 and HSV-2 in viral suspension tests. At noncytotoxic concentrations of TTO plaque formation was reduced by 98.2% and 93.0% for HSV-1 and HSV-2, respectively. Virus titers were reduced significantly with TTO. In order to determine the mode of TTO’s antiviral action, cells were pretreated before viral infection or viruses were incubated with TTO before infection, during adsorption or after penetration into the host cells. Plaque formation was clearly reduced, when herpes simplex virus was pretreated with the TTO prior to adsorption. These results indicate that TTO affect the virus before or during adsorption, but not after penetration into the host cell and so is capable of exerting a direct antiviral effect on HSV. Although the active antiherpes components of TTO are not yet known, their possible application as antiviral agents in recurrent herpes infection is promising The antiviral effect of 12 essential oils (including TTO) on herpes simplex virus type-1 (HSV-1) replication was examined in vitro. TTO was shown to exert most of its activity on free virus, where replication ability of HSV-1 was suppressed completely by incubation of HSV-1 with 1% TTO at 4 C for 24 h, even at a concentration of 0.1% TTO, reduced plaque formation by approximately 10%. When Vero cells were treated with 0.1% TTO before or after viral adsorption, no antiviral activity was found, which suggests that the antiviral activity of TTO may be due to the direct interaction with virions Eighteen patients with recurrent herpes labialis (cold sores) were divided equally into two patient groups, where either 6% TTO gel or placebo gel was administered 5-times daily. The outcome of the study demonstrated that the median time to reepithelization of 9 days for TTO versus 12.5 days for placebo, was not significant. TTO may be a potentially useful cheaper alternative, acceptable to patients, and which poses little threat of inducing resistance to systemic antiviral agents
3
4
ARTICLE IN PRESS Successful topical treatment of hand warts reports to date on its activity against human papilloma virus (HPV) infection. Of these HSV reports (see Table 1), two detailed in vitro plaque reduction assays and the other report described an in vivo clinical trial. From these reports, the activity and topical treatment of HSV with TTO proved encouraging and a basis to explore activity and treatment against other viral agents, such as HPV, given that both HSV and HPV are doublestranded DNA viruses. Warts are caused by HPV infection, where HPV is a member of the Papovaviridae virus family of approximately 45–55 nm and which lacks an envelope. Conventional medical treatment of skin warts may involve destruction by freezing in liquid nitrogen, as well as topical application of salicyclic acid and podophyllin. Patients have complained of excessive pain due to liquid nitrogen treatments and prolonged treatment times of salicyclic acid and podophyllin of several weeks, which may effect treatment compliance in such cases. Employment of TTO itself may carry the risk of allergy and skin irritation in certain individuals; therefore, patients need to be made aware of such potential problems. In this case, employment of TTO proved efficacious with no side effects to the
227 patient, where only the infected area was affected by the oil, in contrast to treatment with salicyclic acid, where surrounding skin can be damaged. To advance the use of this essential oil in the treatment of skin warts, a randomized clinical trial is urgently needed to allow an evidence-based approach to the endorsement of TTO for this indication, particularly to guide on minimum concentration used and minimum duration of treatment.
References 1. Carson CF, Hammer KA, Riley TV. Melaleuca alternifolia (tea tree) oil: a review of antimicrobial and other medicinal properties. Clin Microbiol Rev 2006;9:50–62. 2. Schnitzler P, Scho ¨n K, Reichling J. Antiviral activity of Australian tea tree oil and eucalyptus oil against herpes simplex virus in cell culture. Pharmazie 2001;56:343–7. 3. Minami M, Kita M, Nakaya T, Yamamoto T, Kuriyama H, Imanishi J. The inhibitory effect of essential oils on herpes simplex virus type-1 replication in vitro. Microbiol Immunol 2003;47:681–4. 4. 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: 450–1.
www.elsevierhealth.com/journals/ctnm
Successful topical treatment of hand warts in a paediatric patient with tea tree oil (Melaleuca alternifolia) B. Cherie Millar, John E. Moore Northern Ireland Public Health Laboratory, Department of Bacteriology, Belfast City Hospital, Lisburn Road, Belfast, Northern Ireland BT9 7AD, UK
KEYWORDS Warts; Tea tree oil; TTO; Essential oils; Human papilloma virus; HPV; Dermatology
Summary Tea tree oil (TTO) (Melaleuca alternifolia) has been used recently as an effective topical application for the treatment of skin infections due to a variety of aetiological microbial agents, including mainly bacterial infections. We detail the first report in the peer-reviewed literature of the successful treatment with TTO of a paediatric patient with warts on her right middle finger. TTO was applied topically once daily to the lesions for 12 days, with a successful outcome, including complete re-epithelization of the infected areas. The case highlights the potential use of TTO in the treatment of common warts due to human papilloma virus. & 2008 Elsevier Ltd. All rights reserved.
Case study A seven-year-old girl presented with six warts on the skin associated with the distal phalanges of her right middle finger. On examination, her finger appeared distorted due to the presence of the warts, which were located on both the dorsal and aspect of the finger, as well as on the tip of the finger. More recently, she complained of growing discomfort associated with the presence of the warts in writing and playing the piano. There were no lesions elsewhere on her body. The patient had a history of recurrent warts at the same anatomical Corresponding author. Tel.: +44 28 9026 3554;
fax: +44 28 9026 3991. E-mail address: [email protected] (J.E. Moore).
location, which had been treated topically with salicylic acid (12% w/w) and lactic acid (4% w/w) for several weeks, which resulted in a temporary removal of the warts, before they recurred in greater numbers. Given this history, it was decided on this occasion to treat the warts with topical tea tree oil (TTO) (Melaleuca alternifolia). One hundred percent TTO (Holland and Barrett Ltd., Nuneaton, Warwickshire, UK) was applied with sterile cotton wool swabs to each of the lesions, each evening after bathing and prior to sleep. After 5 days, all warts had considerably reduced in size, with little deformity to the digit and after a further 7 days, there was no evidence of the presence of warts, at which point, treatment was discontinued. There has been no recurrence of the lesions to date.
1744-3881/$ - see front matter & 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.ctcp.2008.05.003
ARTICLE IN PRESS 226
B.C. Millar, J.E. Moore
In recent years, TTO has become a widely used treatment for a wide variety of conditions, ranging from the treatment of head lice to ulcers and other infectious diseases.1 Although this anecdotal evidence of its efficacy is widespread and abundant amongst practitioners of complementary medicine,
Table 1
there has only been a limited number of published clinical studies, examining the efficacy of TTO against bacterial, fungal and protozoal infections. In particular, there have only been three published reports on the efficacy of TTO solely against herpes simplex virus (HSV),2–4 and there have been no
Summary of reports on the antiviral properties of tea tree oil.
Viral agent
Study type
Main findings of study with respect to TTO activity
Ref.
Herpes simplex virus (HSV) (Types 1 and II)
In vitro plaque reduction assay
2
Herpes simplex virus (HSV Type 1)
In vitro plaque reduction assay
Herpes simplex virus (HSV Type 1)
Randomized control trial (RCT)/ investigator blinded
Cytotoxicity of TTO was evaluated in a standard neutral red dye uptake assay. Toxicity of TTO was moderate for RC-37 cells and approached 50% (TC50) at concentrations of 0.006%. Antiviral activity of TTO against herpes simplex virus type 1 (HSV-1) and herpes simplex virus type 2 (HSV-2) was tested in vitro on RC-37 cells using a plaque reduction assay. The 50% inhibitory concentration (IC50) of TTO for herpes simplex virus plaque formation was 0.0009% and 0.0008% for HSV-1 and HSV-2, respectively, and TTO exhibited high levels of virucidal activity against HSV-1 and HSV-2 in viral suspension tests. At noncytotoxic concentrations of TTO plaque formation was reduced by 98.2% and 93.0% for HSV-1 and HSV-2, respectively. Virus titers were reduced significantly with TTO. In order to determine the mode of TTO’s antiviral action, cells were pretreated before viral infection or viruses were incubated with TTO before infection, during adsorption or after penetration into the host cells. Plaque formation was clearly reduced, when herpes simplex virus was pretreated with the TTO prior to adsorption. These results indicate that TTO affect the virus before or during adsorption, but not after penetration into the host cell and so is capable of exerting a direct antiviral effect on HSV. Although the active antiherpes components of TTO are not yet known, their possible application as antiviral agents in recurrent herpes infection is promising The antiviral effect of 12 essential oils (including TTO) on herpes simplex virus type-1 (HSV-1) replication was examined in vitro. TTO was shown to exert most of its activity on free virus, where replication ability of HSV-1 was suppressed completely by incubation of HSV-1 with 1% TTO at 4 C for 24 h, even at a concentration of 0.1% TTO, reduced plaque formation by approximately 10%. When Vero cells were treated with 0.1% TTO before or after viral adsorption, no antiviral activity was found, which suggests that the antiviral activity of TTO may be due to the direct interaction with virions Eighteen patients with recurrent herpes labialis (cold sores) were divided equally into two patient groups, where either 6% TTO gel or placebo gel was administered 5-times daily. The outcome of the study demonstrated that the median time to reepithelization of 9 days for TTO versus 12.5 days for placebo, was not significant. TTO may be a potentially useful cheaper alternative, acceptable to patients, and which poses little threat of inducing resistance to systemic antiviral agents
3
4
ARTICLE IN PRESS Successful topical treatment of hand warts reports to date on its activity against human papilloma virus (HPV) infection. Of these HSV reports (see Table 1), two detailed in vitro plaque reduction assays and the other report described an in vivo clinical trial. From these reports, the activity and topical treatment of HSV with TTO proved encouraging and a basis to explore activity and treatment against other viral agents, such as HPV, given that both HSV and HPV are doublestranded DNA viruses. Warts are caused by HPV infection, where HPV is a member of the Papovaviridae virus family of approximately 45–55 nm and which lacks an envelope. Conventional medical treatment of skin warts may involve destruction by freezing in liquid nitrogen, as well as topical application of salicyclic acid and podophyllin. Patients have complained of excessive pain due to liquid nitrogen treatments and prolonged treatment times of salicyclic acid and podophyllin of several weeks, which may effect treatment compliance in such cases. Employment of TTO itself may carry the risk of allergy and skin irritation in certain individuals; therefore, patients need to be made aware of such potential problems. In this case, employment of TTO proved efficacious with no side effects to the
227 patient, where only the infected area was affected by the oil, in contrast to treatment with salicyclic acid, where surrounding skin can be damaged. To advance the use of this essential oil in the treatment of skin warts, a randomized clinical trial is urgently needed to allow an evidence-based approach to the endorsement of TTO for this indication, particularly to guide on minimum concentration used and minimum duration of treatment.
References 1. Carson CF, Hammer KA, Riley TV. Melaleuca alternifolia (tea tree) oil: a review of antimicrobial and other medicinal properties. Clin Microbiol Rev 2006;9:50–62. 2. Schnitzler P, Scho ¨n K, Reichling J. Antiviral activity of Australian tea tree oil and eucalyptus oil against herpes simplex virus in cell culture. Pharmazie 2001;56:343–7. 3. Minami M, Kita M, Nakaya T, Yamamoto T, Kuriyama H, Imanishi J. The inhibitory effect of essential oils on herpes simplex virus type-1 replication in vitro. Microbiol Immunol 2003;47:681–4. 4. 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: 450–1.