دانلود رایگان ترجمه مقاله درمان شوره سر با شامپوی 5٪ روغن درخت چای – NCBI 2002

درمان شوره سر با شامپوی 5٪ روغن درخت چای

Treatment of dandruff with 5% tea tree oil shampoo

Abstract

Background: Dandruff appears to be related to the yeast Pityrosporum ovale. Tea tree oil has antifungal properties with activity against P ovale and may be useful in the treatment of dandruff. Objective: We conducted a randomized, single-blind, parallel-group study to investigate the efficacy and tolerability of 5% tea tree oil and placebo in patients with mild to moderate dandruff. Methods: One hundred twenty-six male and female patients, aged 14 years and older, were randomly assigned to receive either 5% tea tree oil shampoo or placebo, which was used daily for 4 weeks. The dandruff was scored on a quadrant-area-severity scale and by patient self-assessment scores of scaliness, itchiness, and greasiness. Results: The 5% tea tree oil shampoo group showed a 41% improvement in the quadrant-area-severity score compared with 11% in the placebo group (P < .001). Statistically significant improvements were also observed in the total area of involvement score, the total severity score, and the itchiness and greasiness components of the patients’ self-assessments. The scaliness component of patient self-assessment improved but was not statistically significant. There were no adverse effects. Conclusion: Five percent tea tree oil appears to effective and well tolerated in the treatment of dandruff. (J Am Acad Dermatol 2002;47:852-5.)

1 Introduction

Dandruff is characterized by white to whitish yellow, dry, loose scaling and mild pruritus of the scalp, and some would argue that it is a mild form of seborrheic dermatitis. The yeast Pityrosporum ovale is thought to be the causative agent of dandruff,1,2 and this is supported by studies showing that anti-Pityrosporum agents such as zinc pyrithione, selenium sulfide,3 ketoconazole,4 and terbinafine2 are effective in treating dandruff. Tea tree oil is active against a range of microorganisms, including P ovale5 and thus may also be effective in treating dandruff. Tea tree oil (Melaleuca oil) is an essential oil extracted primarily from the leaves of Melaleuca alternifolia, a shrub-like tree native to Australia. Tea tree oil has been used as a natural remedy for a variety of skin complaints for many years. During World War I, it was included in the first-aid kits of Australian troops to treat burns, bites, and infections. Tea tree oil has been used in the treatment of tinea pedis,6 onychomycosis,7 trichomonal vaginitis,8 and acne.9 Tea tree oil is a complex mixture of hydrocarbons and terpenes, consisting of almost 100 substances, although the antimicrobial activity appears to be related to the major component, terpinen-4-ol.10 The minimum inhibitory concentration for P ovale is 0.25% vol/vol.5 There is increasing demand for natural therapies, and tea tree oil is a popular choice. The aim of this study was to assess the effectiveness and tolerability of 5% tea tree oil shampoo compared with placebo in the treatment of mild to moderate dandruff.

PATIENTS AND METHODS

The Central Sydney Area Health Service Ethics Committee approved the study. All patients freely volunteered to participate, and informed consent was obtained. One hundred twenty-six male and female patients aged 14 years or older were recruited by local advertising. After a 2-week washout period during which Johnson’s Baby Shampoo (Johnson and Johnson) was used daily, the patients were randomly assigned to receive either 5% tea tree oil shampoo or the vehicle shampoo as a placebo. Patients were asked to wash their hair daily, leaving the shampoo in for 3 minutes before rinsing, and were free to use a conditioner. Patients were reevaluated after 2 and 4 weeks and did not wash their hair on the day of examination. Dandruff was assessed by the whole scalp lesion score.11 The scalp was divided into quadrants, and for each quadrant, the area of involvement and severity were assessed. The area of involvement was measured on a scale of 1 to 5 in which a score of 1 meant less than 10% involvement, and a score of 5, more than 70% involvement. Severity was measured by a scale of 0 to 3 in which a score of 0 indicated normal skin, and a score of 3, marked erythema with thick confluent plates of yellowish white scales. The whole scalp score was then obtained by multiplying the total area of involvement score by the total severity score. For inclusion in the study, patients were required to have a whole scalp lesion score between 50 and 200, which had not changed by more than 50 after the washout period. Subjective assessments of scaliness of the scalp, itchiness, and greasiness were made on a 10-cm linear analogue scale, with the two extremes being “none” (0) and “worst ever” (10 cm). This study was single-blinded because the distinctive odor of tea tree oil could identify it to those patients familiar with tea tree oil, although this information was not volunteered to patients. Blinding of the investigator was aided by not applying the shampoo on assessment days (to prevent the odor of the shampoo from identifying the patient group) and by avoiding discussions with patients regarding their shampoo. The data were recorded at baseline and 2 and 4 weeks later. Both the whole scalp lesion score and the patient self-assessment were determined without referring to previous measurements. Patients excluded from the study included those with severe dandruff (whole scalp lesion score 200) or unstable dandruff (a change in the whole scalp lesion score 50 after the washout period), seborrheic dermatitis affecting the face and trunk, psoriasis, diabetes mellitus, immunosuppression, chronic disease not stabilized by medication, concurrent anticoagulation or systemic corticosteroid therapy, or a history of hypersensitivity to tea tree oil. A standard deviation of 40% for the whole scalp lesion score was assumed, on the basis of previous work by this department (unpublished data), and it was determined that a sample size of 63 patients per treatment group would be required to have a power of 80% to detect a difference of 20% in the mean percentage change in the whole scalp lesion score with a 2-sided
level of .05. The intention-to-treat population was used, which comprised all patients who were randomly assigned to treatment, used study medication at least once, and had data recorded after baseline evaluation. Analysis of variance was used to compare the means.