A cream containing the chelator DTPA (diethylenetriaminepenta-acetic acid) can prevent contact allergic reactions to metals

Systemic allergic contact dermatitis to palladium, platinum, and titanium: mechanisms, clinical manifestations, prevalence, and therapeutic approaches

Contact dermatitis (CD) is an inflammatory skin disease of eczema that is elicited by chemicals or metal ions that have toxic effects without eliciting a T-cell response (contact elicitation) or by small reactive chemicals that modify proteins and induce innate and adaptive immune responses (contact allergens). The clinical condition is characterized by localized skin rash, pruritus, redness, swelling, and lesions, which are mainly detected by patch tests and lymphocyte stimulation. Heavy metals such as palladium (Pd), platinum (Pt), and titanium (Ti) are ubiquitous in our environment. These heavy metals have shown CD effects as allergic agents. Immunological responses result from the interaction of cytokines and T cells. Occupational metal CD accounts for most cases of work-related cutaneous disorders. In this systematic review, the allergic effects of heavy metals, including Pd, Pt, and Ti, and the mechanisms, clinical manifestations, prevalence, and therapeutic approaches are discussed in detail. Furthermore, the therapeutic approaches introduced to treat CD, including corticosteroids, topical calcineurin inhibitors, systemic immunosuppressive agents, phototherapy, and antihistamines, can be effective in the treatment of these diseases in the future. Ultimately, the insights identified could lead to improved therapeutic and diagnostic pathways.

Nanotechnologies for Preparation and Application of Metallic Nickel

Nanostructured nickel exhibits substantial surface area per unit volume and adjustable optical, electronic, magnetic, and biological properties, that makes nanofabricated nickel highly attractive as regards to its practical application in different fields of chemistry. Technologies on nickel nanomaterials including their simple preparation and modern application are summarized in this review.

Nickel Allergy: Epidemiology, Pathomechanism, Clinical Patterns, Treatment and Prevention Programs

Nickel is the most common cause of contact allergy in the general population and the most frequently detected allergen in patients patch tested for suspected allergic contact dermatitis (ACD). ACD from nickel is a typical type IV hypersensitivity. Nickel allergy is mostly caused by nonoccupational exposure, such as jewelry and clothing decorations, metal tools, medical devices (mainly orthopedic and orthodontic implants, cardiovascular prosthesis), eyeglasses, utensils, keys, pigment for paint, cosmetics, and food (mainly legumes, chocolate, salmon, peanuts). Occupational exposure can involve several workers (mechanics, metalworkers, platers, hairdressers, jewelers, workers in the constructions and electronic industries), classically involving hands and forearms. The classic clinical pattern of ACD caused by nickel is characterized by eczematous dermatitis involving the sites of direct contact with the metal. Non-eczematous-patterns are reported, including lichenoid dermatitis, granuloma annulare, vitiligo-like lesions, dyshidrosiform dermatitis, and vasculitis. In the case of systemic exposure to nickel, sensitized patients could develop systemic contact dermatitis. Patch testing represents the gold standard for the diagnosis of ACD from nickel. Treatment includes avoidance of contact with products containing nickel and the patient's education about the possible use of alternative products. A recent EU nickel directive, regulating the content and release of nickel from products, has caused a decrease of nickel contact allergy in some European countries. Nickel allergy is a relevant issue of public health with significant personal, social, and economic impact. This review summarizes epidemiology, pathomechanism, clinical patterns, treatment, and prevention programs.

Nickel Allergy of the Skin and Beyond

BACKGROUND

Hypersensitization to nickel is one of the most common contact allergies in the modern world and it is considered to be a major cause of contact dermatitis, especially for hand eczema.

OBJECTIVE

The aim of this paper is to describe many faces of the nickel allergy and to find out different diagnostic, potential strategies for treatment and prevention in hypersensitized patients. A personal clinical experience with practical clinical cases of contact dermatitis to nickel has also been presented.

METHODS

Electronic databases on this topic was carried out using PubMed-Medline.

RESULTS

The literature review identified many articles reporting for nickel contact allergy and pointing the metal as number one allergen in the frequency of positive skin patch test reactions in a large population worldwide. Herein, a summary of the current understanding and evidence on nickel allergy with practical approach and proposed recommendations to the dermatologist, general practitioner, and the allergist were prepared.

CONCLUSION

The prevalence of nickel allergy represents an important socio-economical and health issue. Metal is one of the most common sensitizing agents worldwide. The morbidity due to this metal represents the allergic contact dermatitis and it is constantly growing in many countries. There are also cases of systemic allergic contact dermatitis, where they could be easily misdiagnosed as adverse drug reactions, which lead to delay of the correct diagnosis and inappropriate treatment.

Can the Reactivity to Chromate Be Changed in Patch Testing Using a Barrier Cream?

BACKGROUND

The persistent, difficult-to-treat, allergic contact dermatitis from hexavalent chromium in European construction workers has diminished significantly since the legislative measurements that came into force in January 2005. However, sensitization to hexavalent chromium continues to be a problem. Barrier creams have been tried for various allergens with divergent results.

OBJECTIVE

The aim of the study was to investigate the protective capacity of barrier cream candidates against hexavalent chromium in a patch test situation.

METHODS

An experimental study was performed to investigate the reductive properties of glutathione and iron sulfate on the patch test reactivity in chromium-allergic individuals when exposed to hexavalent chromium. In this study, we also investigated the protective properties of a commercially available barrier cream.

CONCLUSIONS

A higher number of volunteers (16/18) showed reactions on the skin treated with the commercially available barrier cream, compared with the untreated skin (13/18) on test reading day 3/4 or day 7. The skin treated with petrolatum or Essex cream showed fewer and less prominent allergic reactions than the skin treated with the commercially available barrier cream.

Skin application of glutathione and iron sulfate can inhibit elicitation of allergic contact dermatitis from hexavalent chromium

BACKGROUND

Allergic contact dermatitis (ACD) caused by hexavalent chromium, Cr(VI), is often severe and difficult to treat. The most common source of exposure to Cr(VI) in Sweden used to be cement, and more recently leather. The contact allergy can be diminished or inhibited if the exposure is decreased or ceases. Barrier creams against different kinds of allergens have been investigated for their protective properties which may offer protection against Cr(VI) exposure.

OBJECTIVES

To investigate the capacity of formulas containing glutathione (GSH) and iron sulfate to inhibit elicitation of ACD in Cr(VI)-allergic individuals when exposed to Cr(VI).

METHODS

In 18 Cr(VI)-allergic volunteers the back was divided into eight patch test areas which were treated with preparations of possible barrier creams, prior to patch testing with a dilution series of potassium dichromate and a buffered extract of cement.

RESULTS

A significant reduction in reactivity to Cr(VI) and cement extract on skin treated with formulas containing GSH or iron sulfate was noticed, compared with untreated skin.

CONCLUSION

Formulas containing GSH or iron sulfate in barrier creams inhibit ACD in individuals allergic to Cr(VI) when applied before exposure to Cr(VI) and cement extract.

Chitosan-Glycerol Gel as Barrier Formulation for Metal Allergy

Metal-induced allergic contact dermatitis, particularly nickel, affects over 10% of the general population. Herein, chitosan-glycerol gel as protective barrier formulation was synthesized by neutralization reaction with an aim to reduce metal-ion diffusion into the skin to prevent allergy. Active functional groups in chitosan-glycerol gel were able to capture allergenic metal ions present in artificial sweat solution. The efficacy of the barrier formulation against nickel-ion penetration was evaluated ex vivo using pig skin. We found that the percutaneous absorption of nickel ion reduced by ∼98% when chitosan-glycerol gel was used as a barrier formulation.

The Many Faces of Graphene as Protection Barrier. Performance under Microbial Corrosion and Ni Allergy Conditions

In this work we present a study on the performance of CVD (chemical vapor deposition) graphene coatings grown and transferred on Ni as protection barriers under two scenarios that lead to unwanted metal ion release, microbial corrosion and allergy test conditions. These phenomena have a strong impact in different fields considering nickel (or its alloys) is one of the most widely used metals in industrial and consumer products. Microbial corrosion costs represent fractions of national gross product in different developed countries, whereas Ni allergy is one of the most prevalent allergic conditions in the western world, affecting around 10% of the population. We found that grown graphene coatings act as a protective membrane in biological environments that decreases microbial corrosion of Ni and reduces release of Ni²⁺ ions (source of Ni allergic contact hypersensitivity) when in contact with sweat. This performance seems not to be connected to the strong orbital hybridization that Ni and graphene interface present, indicating electron transfer might not be playing a main role in the robust response of this nanostructured system. The observed protection from biological environment can be understood in terms of graphene impermeability to transfer Ni²⁺ ions, which is enhanced for few layers of graphene grown on Ni. We expect our work will provide a new route for application of graphene as a protection coating for metals in biological environments, where current strategies have shown short-term efficiency and have raised health concerns.

Nanoparticles reduce nickel allergy by capturing metal ions

Approximately 10% of the population in the USA suffer from nickel allergy, and many are unable to wear jewellery or handle coins and other objects that contain nickel. Many agents have been developed to reduce the penetration of nickel through skin, but few formulations are safe and effective. Here, we show that applying a thin layer of glycerine emollient containing nanoparticles of either calcium carbonate or calcium phosphate on an isolated piece of pig skin (in vitro) and on the skin of mice (in vivo) prevents the penetration of nickel ions into the skin. The nanoparticles capture nickel ions by cation exchange, and remain on the surface of the skin, allowing them to be removed by simple washing with water. Approximately 11-fold fewer nanoparticles by mass are required to achieve the same efficacy as the chelating agent ethylenediamine tetraacetic acid. Using nanoparticles with diameters smaller than 500 nm in topical creams may be an effective way to limit the exposure to metal ions that can cause skin irritation.

Metal allergy--a review on exposures, penetration, genetics, prevalence, and clinical implications

The prevalence of metal allergy is high in the general population, and it is estimated that up to 17% of women and 3% of men are allergic to nickel and that 1-3% are allergic to cobalt and chromium. Among dermatitis patients, the prevalence of metal allergy is even higher. Metal allergy is mainly an environmental disorder although null mutations in the filaggrin gene complex were recently found to be associated with nickel allergy and dermatitis. Environmental metal exposures include jewelry, buttons, clothing fasteners, dental restorations, mobile phones, and leather. Although consumer exposure is responsible for most cases of metal allergy, the importance of occupational metal exposure remains present and should always be taken into consideration when one interprets allergic patch test reactions to metals. Traditionally, nickel, cobalt, and chromium have been the most important contact allergens. However, recently, gold and palladium have drawn much attention as the prevalence of contact allergy to these metals is high. Palladium allergy is mainly a result of cross-sensitization to nickel, whereas gold allergy is rarely clinically relevant when one takes its high prevalence into account. The epidemiology of metal allergy has recently changed in Europe as nickel allergy among ear-pierced Danish women has decreased following regulatory intervention on nickel release from consumer products. In the United States, the prevalence of nickel allergy is still increasing, which may be explained by the absence of regulation. The prevalence of chromium allergy is increasing in the United States, Singapore, and Denmark among dermatitis patients. This increase is significantly associated with leather exposure in Denmark. Metal allergy may result in allergic contact dermatitis and systemic allergic (contact) dermatitis. Furthermore, metal allergy has been associated with device failure following insertion of intracoronary stents, hip and knee prostheses, as well as other implants. This area is in need of more research.

Management of contact dermatitis due to nickel allergy: an update

Nickel is the major cause of allergic contact dermatitis in the general population, both among children and adults, as well as in large occupational groups. This metal is used in numerous industrial and consumer products, including stainless steel, magnets, metal plating, coinage, and special alloys, and is therefore almost impossible to completely avoid in daily life. Nickel contact dermatitis can represent an important morbidity, particularly in patients with chronic hand eczema, which can lead to inability to work, a decrease in quality of life and significant healthcare expenses. Therefore, its management is of great importance. This article reviews diagnostic, preventive and therapeutic strategies in this field.

In vivo skin irritation potential of a Castanea sativa (Chestnut) leaf extract, a putative natural antioxidant for topical application

Topical application of natural antioxidants has proven to be effective in protecting the skin against ultraviolet-mediated oxidative damage and provides a straightforward way to strengthen the endogenous protection system. However, natural products can provoke skin adverse effects, such as allergic and irritant contact dermatitis. Skin irritation potential of Castanea sativa leaf ethanol:water (7:3) extract was investigated by performing an in vivo patch test in 20 volunteers. Before performing the irritation test, the selection of the solvent and extraction method was guided by the 1,1-diphenyl-2-picryl hydrazyl (DPPH) free radical scavenging test and polyphenols extraction (measured by the Folin Ciocalteu assay). Iron-chelating activity and the phenolic composition (high performance liquid chromatography/diode array detection) were evaluated for the extract obtained under optimized conditions. The extraction method adopted consisted in 5 short extractions (10 min.) with ethanol:water (7:3), performed at 40 degrees. The IC(50) found for the iron chelation and DPPH scavenging assays were 132.94 +/- 9.72 and 12.58 +/- 0.54 microg/ml (mean +/- S.E.M.), respectively. The total phenolic content was found to be 283.8 +/- 8.74 mg GAE/g extract (mean +/- S.E.M.). Five phenolic compounds were identified in the extract, namely, chlorogenic acid, ellagic acid, rutin, isoquercitrin and hyperoside. The patch test carried out showed that, with respect to irritant effects, this extract can be regarded as safe for topical application.

Final Report on the Safety Assessment of Pentasodium Pentetate and Pentetic Acid as Used in Cosmetics

Pentasodium Pentetate and Pentetic Acid function as chelating agents in cosmetics. Pentasodium Pentetate is readily soluble in water, but the corresponding free acid is not. Pentasodium Pentetate is used in almost 400 cosmetic products over a wide range of product categories, although it is mostly used in hair dyes and colors at use concentrations of 0.1% to 1.0%. Pentetic Acid is used in 150 cosmetic products, mostly in hair dyes and colors. Chelating agents are used in cosmetics to remove calcium and magnesium cations, which impede foaming and cleansing performance and which can cause a haze in clear liquids. The acute oral LD50 of Pentasodium Pentetate in rats was >5 g/kg. The acute dermal LD50 of Pentapotassium Pentetate using rats was reported to be >2 g/kg. The intraperitonal LD50 of Pentetic Acid was reported to be 585 mg/kg. Short-term studies of the calcium and sodium salts of Pentetic Acid in male mice demonstrated no dose-related toxicity over the dose range of 10, 100, and 250 mg/kg. In a 4-week dermal toxicity study, daily topical application of 0.05% Pentasodium Pentetate to shaved and abraded rabbit skin produced moderate erythema after the first week and throughout the study, but no systemic tox-icity. Pentasodium Pentetate or Pentapotassium Pentetate applied to intact albino rabbit skin were not irritating. A 40% solution of Pentapotassium Pentetate was not sensitizing in a guinea pig maximization test. The no observed adverse effect level (NOAEL) for rats given 40% Pentapotassium Pentetate by oral gavage was reported to be 83 mg/kg day-1. Subchronic inhalation evaluation of a bath freshener containing 0.05% or 0.09% Pentasodium Pentetate using albino rats determined that there was no cumulative systemic toxicity attributable to the ingredient at either concentration. The no observed effect level (NOEL) for maternal toxicity in pregnant rats was 400 mg/kg body weight and for fetal toxicity was 100 mg/kg body weight. Another reproductive toxicity study evaluated Pentetic Acid–Zn with and without sodium chloride in pregnant C57/B1 Dougherty mice. No toxicity was found without added sodium chloride. Pentapotassium Pentetate was not muta-genic in an Ames test, with or without metabolic activation. The same material tested in Chinese hamster ovary cells was not clas-togenic. Calcium Pentetate at 1.351 µg/ml produced a statistically significant increase in the number of sister-chromatid exchanges. Pentasodium Pentetate is nonirritating to moderately irritating, but not a sensitizer in clinical tests. A human comedogenicity (acne promotion) test using Pentasodium Pentetate found no effect. Although data are lacking on the dermal penetration of these two ingredients, other chelating agents such as EDTA do not penetrate the skin, so it is likely that Pentasodium Pentetate and Pentetic Acid also would not penetrate. The high water solubility of Pentasodium Pentetate and the low water solubility of Pentetic Acid also support that their dermal penetration will be low. Other chelating agents, including EDTA and its salts, have been determined to be safe in the current practices of use in cosmetics. Meta-, Tri-, and Hexam-etaphosphate salts are chelating agents determined to be safe in the current practices of use in cosmetics. Metasilicate salts were found to be safe as chelating agents in cosmetics when formulated to avoid irritation. Overall, these data were considered sufficient to support the safety of Pentesodium Pentetate and Pentetic Acid as used in cosmetics.

Sensitization to nickel: etiology, epidemiology, immune reactions, prevention, and therapy

Nickel is a contact allergen causing Type I and Type IV hypersensitivity, mediated by reagins and allergen-specific T lymphocytes, expressing in a wide range of cutaneous eruptions following dermal or systemic exposure. As such, nickel is the most frequent cause of hypersensitivity, occupational as well as among the general population. In synoptic form, the many effects that nickel has on the organism are presented to provide a comprehensive picture of the aspects of that metal with many biologically noxious, but metallurgically indispensable characteristics. This paper reviews the epidemiology, the prognosis for occupational and non-occupational nickel allergic hypersensitivity, the types of exposure and resulting immune responses, the rate of diffusion through the skin, and immunotoxicity. Alternatives toward prevention and remediation, topical and systemic, for this pervasive and increasing form of morbidity are discussed. The merits and limitations of preventive measures in industry and private life are considered, as well as the effectiveness of topical and systemic therapy in treating nickel allergic hypersensitivity.

A systematic review of contact dermatitis treatment and prevention

BACKGROUND

Contact dermatitis (CD) is a common occupational disease. There have been no systematic reviews of CD treatment or prevention.

METHODS

Multiple databases were systematically searched. Using independent double review and published quality review criteria, articles were rated as good, fair, or poor. Treatment benefit data were tabulated and conclusions were based on the rated strength of published evidence.

RESULTS

In all, 49 studies met inclusion criteria. Barrier creams containing dimethicone or perfluoropolyethers, cotton liners, and softened fabrics prevent irritant CD. Lipid-rich moisturizers both prevent and treat irritant CD. Topical skin protectant and quaternium 18 bentonite (organoclay) prevent rhus dermatitis. Diethylenetriamine pentaacetic acid (chelator) cream prevents nickel, chrome, and copper dermatitis. Potent or moderately potent steroids effectively treat allergic CD. There were no macrolide immunomodulator trials that met inclusion criteria. This review did not include studies of children, animals, or non-English language publications.

CONCLUSIONS

A limited number of interventions effectively prevent or treat irritant and allergic CD, but well-controlled, outcome-blinded studies, particularly in the area of allergic CD prevention are needed.

Effectiveness of skin protection creams as a preventive measure in occupational dermatitis: a critical update according to criteria of evidence-based medicine

OBJECTIVES

This study attempts to assess the evidence of the generally recommended three-step programme of skin protection in the prevention of occupational skin disease.

METHODS

The following clinical questions, representative of critical appraisal of this preventive measurement, were generated: (1) Can a skincare regimen effectively reduce or eliminate work-related poor skin conditions? (2) Do protective creams prevent harmful substances from penetrating and adhering to the skin? (3) Is the differentiation between pre-exposure and post-exposure products justified by reliable data? Answers were generated according to the method used in evidence-based medicine by searching the literature, critically appraising the results and applying the results to the clinical questions. For our search we decided to use PubMed as the most convenient access to Medline and because, in contrast to other databases, this access is available free of charge.

RESULTS

To investigate the efficacy of barrier creams as pre-exposure skin protectors various in vitro and in vivo test methods have been developed. Over the past years the test techniques have been improved in order to adopt a real workplace situation. Efforts for standardisation of evaluation criteria have been made, too. Nevertheless, there is a lack of placebo-controlled, randomised clinical trials evaluating the benefit of these products in the prevention of occupational contact dermatitis under real workplace conditions. The literature data are conflicting; some publications report on the positive aspects of skin protection, whereas others stress the negative ones.

CONCLUSION

Not enough data have been accumulated for one to prove the benefit of skin protection measures under real workplace condition. Up to now, it is almost unclear if the various in vitro and in vivo methods used are suitable to simulate real workplace conditions and if these test results can be related to real occupational exposure. For the evidence-based recommendation of skin protection, further studies, especially under daily working conditions evaluating the contribution of each single element of skincare programme (products, frequency of application and education programme) are needed.

Nickel-elicited systemic contact dermatitis

20 patients with systemic contact dermatitis due to nickel are described. Of these patients, 15 were female and 5 were male. Their mean age was 24.8 years (16-51 years). All had experienced contact dermatitis in the umbilical area due to continual contact with metal belt-buckles or buttons. Then, with long- or short-term aggravation of such periumbilical dermatitis, commonly in summer, lesions spread to other sites such as the side of the neck, the flexures of the extremities, etc. All patients showed a positive patch test to nickel sulphate (2.5% in petrolatum) and the dimethylglyoxime test demonstrated the presence of free nickel on metal buttons or belt-buckles. Punch biopsies performed in 7 patients showed subacute dermatitis. After avoidance of continual exposure to objects containing nickel and foods rich in nickel, as well as treatment with oral antihistamines and topical corticosteroids, all patients improved or cleared. It has been reported that nickel can cause systemic contact dermatitis by some internal systemic route, such as oral intake, transfusion, inhalation, implantation of metal medical devices, etc. In our patients, we found that continual local skin contact could also elicit systemic contact dermatitis.

Copper allergy revisited

BACKGROUND

Positive patch tests to copper sulfate are regularly observed, although copper is reported as a rare allergen with a low sensitizing potential. Usually they are claimed to be irritant and unspecific.

OBJECTIVE

The aim of this study was to assess the relevance and the diagnostic value of positive reactions to copper.

METHODS

A total of 2660 routine patch tests were analyzed for positive reactions to copper and other metal allergens: copper, 3.53%; nickel, 21.02%; palladium, 5.90%; cobalt, 3.31%.

RESULTS

Reactions to copper and nickel were highly significantly associated with each other. Twenty-six patients with a positive routine test to copper were retested. The reproducibility was modest (38%), but again significantly associated with nickel sensitization.

CONCLUSION

These clinical data support a copper-nickel cross-reactivity concept on T-cell level based on recently published molecular data. We conclude that positive patch tests to copper are mostly specific; however, they are usually of low clinical relevance.