Allergic contact dermatitis to cosmetics containing Melaleuca alternifolia (tea tree oil)

INTRODUCTION: Melaleuca alternifolia is a coniferous tree found in tropical regions, the needles contain an essential oil that is used in medical and cosmetic products. The essential oil contains turpentines (limonene, alpha-pinene, phellandrene) that are potentially allergenic.PATIENTS AND METHODS: In 1997, 1216 patients were patch tested in our dermatoligic unit. Fourteen of them tested because of eczema used products containing tea tree oil. The patients used creams, hair products and essential oils containing Melaleuca alternifolia for cosmetic reasons and to treat skin affections. They were patch tested for a standard panel of allergens, topical emulgators, perfumes, plants, topical medications, metal, gloves, topical disinfectants and preservatives, dental products and rubber derivatives. Products containing Melaleuca alternifolia were tested concentrated or diluted.RESULTS: We report on 7 cases of patients with an allergic contact dermatitis due to tea tree oil. Two of them also exhibited from a delayed type IV hypersensitivity towards fragrance-mix or colophony suggesting the possibility of cross reaction or an allergic group reaction caused by contamination of the colophony with the volatile fraction of turpentines.DISCUSSION: The allergic potential of low concentrations of Melaleuca alternifolia is presumed to be low on healthy skin. Photoaged Melaleuca alternifolia must be considered to be a stronger sensitizer.     

Terpinen-4-ol, the main component of Melaleuca alternifolia (tea tree) oil inhibits the in vitro growth of human melanoma cells

The search for innovative therapeutic approaches based on the use of new substances is gaining more interest in clinical oncology. In this in vitro study the potential anti-tumoral activity of tea tree oil, distilled from Melaleuca alternifolia, was analyzed against human melanoma M14 WT cells and their drug-resistant counterparts, M14 adriamicin-resistant cells. Both sensitive and resistant cells were grown in the presence of tea tree oil at concentrations ranging from 0.005 to 0.03%. Both the complex oil (tea tree oil) and its main active component terpinen-4-ol were able to induce caspase-dependent apoptosis of melanoma cells and this effect was more evident in the resistant variant cell population. Freeze-fracturing and scanning electron microscopy analyses suggested that the effect of the crude oil and of the terpinen-4-ol was mediated by their interaction with plasma membrane and subsequent reorganization of membrane lipids. In conclusion, tea tree oil and terpinen-4-ol are able to impair the growth of human M14 melanoma cells and appear to be more effective on their resistant variants, which express high levels of P-glycoprotein in the plasma membrane, overcoming resistance to caspase-dependent apoptosis exerted by P-glycoprotein-positive tumor cells.     

Safety, efficacy and provenance of tea tree (Melaleuca alternifolia) oil

The identity, sources and composition of tea tree (Melaleuca alternifolia) oil are discussed, and earlier errors in the literature indicated. Reports of both therapeutic and allergenic effects are reviewed.     

Allergy to tea tree oil: retrospective review of 41 cases with positive patch tests over 4.5 years

Tea tree oil use is increasing, with considerable interest in it being a 'natural' antimicrobial. It is found in many commercially available skin and hair care products in Australia. We retrospectively reviewed our patch test data at the Skin and Cancer Foundation Victoria over a 4.5-year period and identified 41 cases of positive reactions to oxidized tea tree oil of 2320 people patch-tested, giving a prevalence of 1.8%. The tea tree oil reaction was deemed relevant to the presenting dermatitis in 17 of 41 (41%) patients. Of those with positive reactions, 27 of 41 (66%) recalled prior use of tea tree oil and eight of 41 (20%) specified prior application of neat (100%) tea tree oil. Tea tree oil allergic contact dermatitis is under-reported in the literature but is sufficiently common in Australia to warrant inclusion of tea tree oil, at a concentration of 10% in petrolatum, in standard patch-test series. Given tea tree oil from freshly opened tea tree oil products elicits no or weak reactions, oxidized tea tree oil should be used for patch testing.     

The antibacterial activity of tea in vitro and in vivo (in patients with impetigo contagiosa)

A total number of 104 patients with impetigo contagiosa was included in this study. They were 47 females (45.2%) and 57 males (54.8%). Their ages ranged from one month to 40 years with a median of 4 years. This study was divided into two parts: PART I (in vitro): Thirty-five patients were swabbed to determine the microbiology of impetigo contagiosa which included 33 isolates of pure S. aureus (94.3%) and 2 of a combination of S. aureus and Streptococcus pyogenes (5.7%). The antibacterial effect of tea liquor (lotion) against S. aureus proved very effective. Antibiotic sensitivity was done for all bacterial isolates of S. aureus. PART II (in vivo): The antibacterial effects of tea liquor and ointment were tested by treating 64 patients with impetigo contagiosa. Tea ointment was very effective with a cure rate of 81.3%. Forty patients were taken as controls and divided into two groups. The first one was given an ointment containing Framycetin and gramicidin (soframycin) with a cure rate of 72.2%; the other group was given oral cephalexin with a cure rate of 78.6%. To the best of our knowledge, this study was the first one which demonstrated the anti-bacterial action of crude tea in vivo, against impetigo contagiosa. Clinical data about impetigo are also included in this study.     

Biological behavior of Sarcoptes scabiei var. suis in swine epidermis. A scanning electron microscopy study in hyperkeratotic (or Norwegian) scabies of swine

The behaviour of Sarcoptes scabiei var. suis has been studied in hyperkeratotic scabies of pigs (fig. 1). The scanning electron microscope enabled us to observe the outer surface of the eggs in the burrow and even within the cut body of the fertilized female mite (fig. 2). Early events during hatching of the eggs and the first steps of the newborn larva (fig. 3) are shown. The presence of crystals containing calcium and phosphate is shown to occur in places where huge amounts of faecal material are collected (fig. 4). Although some of these aspects have not been published previously we observed many similarities in behavior between Sarcoptes scabiei var. hominis and suis in their respective hosts affected with hyperkeratotic scabies. As to the therapeutic aspect of scabies in humans, carefully selected drugs currently used in the systemic treatment of scabies in pigs would be worth a trial in patients difficult to treat.     

Skin fibroblast activity in pretibial myxoedema and the effect of octreotide (Sandostatin®) in vitro

The accumulation of glycosaminoglycans in the skin in pretibial myxoedema appears to be a response by local fibroblasts to a stimulating factor in the patient's serum, but the identity of the factor, its ability to stimulate skin fibroblasts as opposed to cultured thyroid cells, and the specificity of its effect to pretibial skin fibroblasts, are all controversial. We have studied fibroblasts cultured from the lesional skin of two women with pretibial myxoedema, and compared their proliferation and secretion of glycosaminoglycans with those of fibroblasts from the patients' forearms and from the forearm skin of two normal subjects. We found that in the presence of the patients' sera all six lines of fibroblasts secreted more glycosaminoglycans [205±21% (SD)] than with normal human sera (147±19%), or fetal calf serum (100%). Fibroblast proliferation showed the same pattern of differences: patients' sera 142±22%; normal human sera 116±9%, and fetal calf serum 100%. These experiments confirm the presence of a serum factor in pretibial myxoedema which is capable of stimulating the activity of skin fibroblasts in vitro, and show that its effects are not restricted to fibroblasts from pretibial skin or to those grown from the skin of the patients. Proliferation of normal fibroblasts cultured in medium supplemented with fetal calf serum was reduced by Sandostatin® (octreotide), but it failed to inhibit their secretion of glycosaminoglycans. In contrast, secretion of glycosaminoglycans by a patient's pretibial skin fibroblasts was almost completely inhibited by 1 mM minoxidil. In the presence of patients' sera Sandostatin® (0.1–10 μg/ml) reduced secretion of glycosaminoglycans by about 50%. Our data support the use of Sandostatin® in pretibial myxoedema, and suggest that it may suppress fibroblast glycosaminogly- can secretion within the skin via depletion of insulin-like growth factor or the blocking of its effect.     

The effect of a sulfonated shale oil extract (ichthyol) on the migration of human neutrophilic granulocytes in vitro

Summary The sulfonated shale oil extract, Ichthyol, was studied for its effect on the migration of human neutrophilic granulocytes by the Boyden chamber technique. When presented to the cells in a concentration gradient, Ichthyol induced a directed migration. There was little or no chemokinetic effect of Ichthyol when added to the cell compartment of the Boyden chamber. The chemotactic migration towards the tripeptides, formyl-methionyl-leucyl-phenylalanine and formyl-norleucyl-leucyl-phenylalanine, towards the arachidonic acid-derived eosinophil chemotactic factor released from neutrophils by the ionophore A 23187, and towards complementderived chemotactic activity of normal human serum was inhibited or abrogated by Ichthyol. The Ichthyol effect on f-MLP chemotaxis could be partly overcome by excessive f-MLP concentrations. It was reversible when Ichthyol-incubated cells were washed and resuspended in regular buffer. It is suggested that various substances contained in Ichthyol interacted with either the chemotactic factors or the cell membrane or both and thus blocked cell stimulation. The results could help to explain the cell accumulation and abscess formation observed with Ichthyol in inflammatory skin lesions and the anti-inflammatory properties of the drug.     

Higher cyclobutane pyrimidine dimer and (6-4) photoproduct yields in epidermis of normal humans with increased sensitivity to ultraviolet B radiation

Cyclobutane pyrimidine dimer (CPD) and (6-4) photoproduct induced in the epidermis of five Japanese volunteers exposed to ultraviolet (UVB) radiation were measured with monoclonal antibodies specific for each photoproduct. The volunteers comprised two individuals who are sensitive to solar irradiation (low minimal erythema dose [MED]) and three who are less sensitive. The yields of CPD and (6-4) photoproduct were within similar ranges after 1 MED or 3 MED doses. The yields of both photoproducts after the same dose of irradiation (120 mJ/cm²) were higher in UV-sensitive individuals than in less sensitive individuals. By 24 h after irradiation, an average of 60% of CPD had been removed after the 1 MED dose, 27% after the 3 MED dose and 34% after 120 mJ/cm². The (6-4) photoproduct was removed within 24 h, independently of the dose of UVB tested. These data suggest that DNA photoproducts participate in initiating UVB-induced erythema, and partially explain why individuals with higher sensitivity to UVB have a higher risk of UV-induced skin cancer.     

In vitro short-time killing activity of povidone-iodine (Isodine Gargle) in the presence of oral organic matter

In order to estimate the clinical efficacy of a povidone-iodine oral antiseptic (PVP-I) on oral bacterial infectious diseases, we studied the effect of oral organic matter on the in vitro killing activity of PVP-I. In addition, we compared the in vitro short-time killing activity of PVP-I with those of other oral antiseptics using mouth-washing and gargling samples collected from healthy volunteers. When any of the mouth-washing and gargling samples was used, the standard (0.23-0.47%) or lower concentrations of PVP-I killed methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, including multidrug-resistant strains, within 15-60 s in the presence of oral organic matter. 0.02% benzethonium chloride (BEC) and 0.002% chlorhexidine gluconate (CHG) did not show effects against MRSA and P. aeruginosa (including multidrug-resistant strains) in mouth-washing and gargling samples even after 60 s. The above-mentioned results show that the in vitro killing activity of the standard concentration of PVP-I was hardly affected by the oral organic matter and that a mouth-washing or gargling solution containing PVP-I has a stronger bactericidal activity than BEC and CHG. Although mouth-washing and gargling samples were obtained from healthy individuals in this study, PVP-I may be used for protection against infections in patients with various diseases, if proper concentrations and usage are encouraged.     

Serological diagnosis of bullous pemphigoid (BP): comparison of the sensitivity of indirect immunofluorescence on salt-split to immunoblotting

Specialized immunological assays are required for the accurate diagnosis of bullous dermatoses such as bullous pemphigoid (BP), epidermolysis bullosa acquisita and bullous lupus erythematosus. The aim of this study was to analyse and compare the sensitivity of indirect immunofluorescence (IF) on salt-split skin and immunoblotting for the detection of circulating autoantibodies in BP. Of the BP patients selected for the study, 74/79 (94%) had circulating autoantibodies detected by at least one of the two methods. Both methods had comparable sensitivity and detected BP-specific autoantibodies in 82-85% of the patients. Because 20% of the patients were found to be positive by only one of the methods, both methods should be used in the diagnosis of BP. Indirect IF on salt-split skin is easier to perform and is preferable in routine analysis, but Western blotting may be used as a complementary assay with sera showing no reactivity on salt-split skin.