Advancing the understanding of allergic contact dermatitis: from pathophysiology to novel therapeutic approaches

Allergic contact dermatitis (ACD) is a common inflammatory skin disease that, especially when the condition becomes chronic, has a high impact on the quality of life and represents a significant disease burden. ACD represents a type IV delayed-type hypersensitivity reaction that is triggered by contact with an allergen in previously sensitized individuals through the activation of allergen-specific T cells. In the acute phase, it is characterized by eczematous dermatitis, which presents with erythema, edema, vesicles, scaling, and intense itch. Non-eczematous clinical forms are also described (lichenoid, bullous, and lymphomatosis). Lichenification is the most common clinical picture in the chronic phase if the culprit allergen is not found or eliminated. ACD can be associated with both occupational and non-occupational exposure to allergens, representing approximately 90% of occupational skin disorders along with irritant contact dermatitis. Patch testing with suspected allergens is required for a diagnosis. Metals, especially nickel, fragrance mix, isothiazolinones, and para-phenylenediamine, are the most commonly positive allergens in patients patch tested for suspected ACD. The treatment goal is to avoid contact with the culprit agent and use topical and/or systemic corticosteroid therapy.

Functional Roles of Exosomes in Allergic Contact Dermatitis

Allergic contact dermatitis (ACD) is an allergen-specific T-cell-mediated inflammatory response, albeit with unclear pathogenesis. Exosomes are nanoscale extracellular vesicles secreted by several cell types and widely distributed in various biological fluids. Exosomes affect the occurrence and development of ACD through immunoregulation among other ways. Nevertheless, the role of exosomes in ACD warrants further clarification. This review examines the progress of research into exosomes and their involvement in the pathogenesis, diagnosis, and treatment of ACD and provides ideas for exploring new diagnostic and treatment methods for this disease.

A comprehensive review on the sources, essentiality and toxicological profile of nickel

This review contains up-to-date knowledge and recent advancements on the essentiality, sources, and toxicological profile of nickel and its different compounds. Nickel is a recognized essential element for several important biological processes like the healthy growth of plants, animals, and soil/water microbes; though an excess amount of nickel intoxicates flora and fauna. Nickel is found to affect the photosynthetic function of higher plants; it can severely degrade soil fertility and causes many chronic diseases in humans. Due to the huge growth in the nickel industry and consumption of nickel-containing products, environmental pollution has become inevitable by the element nickel and also varieties of its by-products through all the phases of making, utilization and dumping. We have focused on the importance of agenda 2030 (UN 17 SDGs) during the preparation of the write-up and have highlighted goals 3, 6, 8, 9, 11, 12, 13, 14, and 15 by elaborately discussing associated points. The plausible molecular mechanism of nickel toxicity is presented in simple diagrams. The article elaborates on possible methods for remediation of nickel toxicity and the treatment of nickel dermatitis and nickel cancer. Recent advancements in the understanding of the dual aspects of nickel as beneficial and a carcinogen are the key subject of this article.

This review contains up-to-date knowledge and recent advancements on the essentiality, sources, and toxicological profile of nickel and its different compounds.

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.

Efficacy of oral supplementation of whey protein in patients with contact dermatitis: A pilot randomized double-blind placebo-controlled clinical trial

Whey protein is a popular dietary product that has numerous health benefits such as immune modulation. In this study, we assessed efficacy of whey protein in management of patients with contact dermatitis (CD) through a double blind, randomized controlled clinical trial in Emam Reza clinic, Shiraz, Iran. Twenty-five patients in each group were randomly assigned to receive whey protein or placebo powder, 30 g in 200 mL warm water at fasting time for 4 weeks. Outcome measures were Dermatology Life Quality Index (DLQI) questionnaire and the Eczema Area and Severity Index (EASI) score. Furthermore, subjective total improvement (assessed by visual analogue scale) was set as the other primary outcome measure. A significant decrease was observed in the scores of EASI, DLQI, and subjective total improvement in the drug group after the intervention compared with the baseline. However, no changes were seen in the placebo group. Moreover, there was a significant reduction in the scores of EASI (P = .002) and subjective total improvement scores (P = .039) over the study period in the drug group compared with the placebo group. According to the results of this study, it seems that oral supplementation of whey protein could improve the symptoms of CD compared with placebo.

Epidemiology of nickel sensitivity: Retrospective cross-sectional analysis of North American Contact Dermatitis Group data 1994-2014

BACKGROUND

Nickel is a common allergen.

OBJECTIVE

To examine the epidemiology of nickel sensitivity in North America.

METHODS

Retrospective, cross-sectional analysis of 44,097 patients patch tested by the North American Contact Dermatitis Group from 1994 to 2014. Nickel sensitivity was defined as a positive patch test for nickel. We evaluated the frequency of nickel sensitivity and patient demographics. For each positive reaction to nickel, we tabulated clinical relevance, occupational relatedness, and exposure sources.

RESULTS

The average frequency of nickel sensitivity was 17.5% (1994-2014). Nickel sensitivity significantly increased over time (from 14.3% in 1994-1996 to 20.1% in 2013-2014 [P < .0001]). Nickel-sensitive patients were significantly more likely to be female, young, nonwhite, and atopic (have eczema and asthma) and/or have dermatitis affecting the face, scalp, ears, neck, arm, or trunk (P values ≤ .0474). Overall, 55.5% of reactions were currently clinically relevant; this percentage significantly increased over time (from 44.1% in 1994-1996 to 51.6% in 2013-2014 [P < .0001]). The rate of occupational relatedness was 3.7% overall, with a significant decrease over time (from 7.9% in 1994-1996 to 1.9% in 2013-2014 [P < .0001]). Jewelry was the most common source of nickel contact.

LIMITATIONS

Tertiary referral population.

CONCLUSIONS

Nickel allergy is of substantial public health importance in North America. The frequency of nickel sensitivity in patients referred for patch testing has significantly increased over a 20-year period.

Survey of urinary nickel in peritoneal dialysis patients

This study surveyed urinary nickel concentrations in peritoneal dialysis (PD) patients, and analyzed the association of urinary nickel concentrations with clinical outcomes and inflammatory biomarkers. In total, 50 PD patients and 50 healthy controls were recruited for this study. All participants were examined for the presence of toxic trace elements (antimony, arsenic, bismuth, cadmium, copper, manganese, mercury, nickel, lead, tellurium, thallium and zinc) in their urine by using inductively coupled plasma mass spectrometry (ICP-MS). It was found that PD patients demonstrated higher urinary nickel concentrations than healthy controls (6.1±3.5 versus 2.8±1.4 μg/L, P<0.001). There were 24 (48.0%) PD patients with normal urinary nickel concentrations, and 26 (52.0%) PD patients with high urinary nickel concentrations. The PD patients with high urinary nickel concentrations demonstrated higher log serum levels of high sensitivity C-reactive protein (0.4±0.5 versus 0.1±0.5 mg/L, P=0.046) than patients with normal urinary nickel concentrations. Furthermore, patients with high urinary nickel concentrations exhibited higher levels of cadmium (1.3±0.9 versus 0.6±0.5 μg/L, P<0.001), copper (7.7±5.7 versus 3.3±1.4 μg/L, P<0.001) and manganese (0.9±1.1 versus 0.4±0.4 μg/L, P=0.023) than patients with normal urinary nickel concentrations. Nevertheless, there were no significant differences in the clinical outcomes between PD patients with high and normal urinary nickel concentrations (P>0.05). Thus, it is concluded that approximately half of the patients undergoing PD had elevated urinary nickel levels, and these patients also had elevated serum levels of high sensitivity C-reactive protein. Nevertheless, no other real correlations were discovered including no impact on patient outcome. Further studies are warranted.

Differentiating allergic and irritant contact dermatitis by high-definition optical coherence tomography: a pilot study

Differentiation of allergic contact dermatitis (ACD) and irritant contact dermatitis (ICD) is important because of different management requirements. Various non-invasive tests have been used in an attempt to improve diagnosis. In irritant dermatitis, thickening of the epidermis has been a constant finding. High-Definition Optical Coherence Tomography (HD-OCT) is a non-invasive real-time three-dimensional imaging technique with cellular resolution for which an adapted algorithmic method for pattern analysis discriminating inflammatory skin diseases has been proposed. The aim of this study was threefold. (1) To evaluate the correlation between HD-OCT features and clinical scores of allergic and irritant patch test reactions. (2) To explore the potential of HD-OCT in optimizing the visual patch test scoring. (3) To assess in vivo the cytological and 3-D micro-architectural differences in skin reaction types between doubtful positive ACD and ICD. Twenty-two volunteers were patch tested using potassium(VI)dichromate, cobalt(II)chloride, nickel(II) sulfate and palladium(II)chloride. Visual patch test scoring and HD-OCT assisted patch test scoring were performed at 48 and 96 h after patch test application according to ECDRG guidelines. Selected HD-OCT features correlated well with clinical severity scores. HD-OCT assessment improved the visual patch test scoring although not significantly. Increased epidermal thickness observed in ICD at first reading was a significant finding useful in differentiating doubtful (+?) ACD from irritant (IR) ICD reactions. In conclusion, HD-OCT might be a unique tool for in vivo non-invasive real-time three-dimensional epidermal thickness measurements helping to differentiate IR from doubtful (+?) reactions in patch testing. Selected HD-OCT features corresponded well with severity of visual scoring. These features might help to quantify the degree of inflammation in inflammatory skin conditions. HD-OCT might help in optimizing visual patch test scoring in some situations.

Properties of experimental copper-aluminium-nickel alloys for dental post-and-core applications

PURPOSE

This study aimed to develop a copper-aluminium-nickel alloy which has properties comparable to that of dental alloys used for dental post and core applications with the reasonable cost.

MATERIALS AND METHODS

Sixteen groups of experimental copper alloys with variants of 3, 6, 9, 12 wt% Al and 0, 2, 4, 6 wt% Ni were prepared and casted. Their properties were tested and evaluated. The data of thermal, physical, and mechanical properties were analyzed using the two-way ANOVA and Tukey's test (α=0.05). The alloy toxicity was evaluated according to the ISO standard.

RESULTS

The solidus and liquidus points of experimental alloys ranged from 1023℃ to 1113℃ and increased as the nickel content increased. The highest ultimate tensile strength (595.9 ± 14.2 MPa) was shown in the Cu-12Al-4Ni alloy. The tensile strength was increased as the both elements increased. Alloys with 3-6 wt% Al exhibited a small amount of 0.2% proof strength. Accordingly, the Cu-9Al-2Ni and Cu-9Al-4Ni alloys not only demonstrated an appropriate modulus of elasticity (113.9 ± 8.0 and 122.8 ± 11.3 GPa, respectively), but also had a value of 0.2% proof strength (190.8 ± 4.8 and 198.2 ± 3.4 MPa, respectively), which complied with the ISO standard requirement (>180 MPa). Alloys with the highest contents of nickel (6 wt% Ni) revealed a widespread decolourisation zone (5.0-5.9 mm), which correspondingly produced the largest cell response, equating positive control.

CONCLUSION

The copper alloys fused with 9 wt% Al and 2-4 wt% Ni can be considered for a potential use as dental post and core applications.

Peripheral blood lymphocyte typing as a useful tool to objectify the oral mucosa patch test in the diagnosis of allergic contact mucositis to nickel

Nickel (Ni) exposure through the intestinal mucosa may cause a hypersensitivity reaction recently defined as allergic contact mucositis (ACM). This condition is identifiable by the oral mucosa patch test (omPT), a qualitative and subjective examination that requires clinical expertise. Our aim was to evaluate if a peripheral blood lymphocyte typing performed before and after the omPT for Ni may be able to objectify this examination for diagnostic purposes. Thirty patients with symptoms referable to the ingestion of Ni-rich foods were subjected to omPT for Ni. Before and after the omPT, each patient underwent blood sampling for the typing of total lymphocytes and their subsets (T, T helper or Th, T cytotoxic or Tc, B, natural killer or NK). Statistical analysis was performed by Student t test and receiver operating characteristic (ROC) curve analysis. According to the omPT outcomes, 18 patients were defined as Ni-sensitive and the remaining 12 as controls. In Ni-sensitive patients, the number of total, T, Th, Tc, and B lymphocytes/μL whole blood increased after the omPT (p<0.0001 for the first three, p=0.0004 and p=0.0001 for the last two lymphocyte types). No omPT-dependent lymphocyte increase was observed in controls. The post/pre omPT cell ratio, especially if calculated for Th lymphocytes, appears to be an effective index for diagnostic purposes (sensitivity=100%, specificity=83.3%, Youden index=0.833, area under curve (AUC)=0.926, p<0.0001). In conclusion, the peripheral blood lymphocyte typing with calculation of post/pre omPT cell ratio has the potential to support the omPT in diagnosing ACM, with the advantage of providing quantitative and objective data.

Immunological characterization of the allergic contact mucositis related to the ingestion of nickel-rich foods

BACKGROUND

The ingestion of nickel (Ni)-rich foods may result in allergic contact mucositis (ACM), a not yet well defined condition identifiable by oral mucosa patch test (omPT). Our aim was to characterize immunologically the ACM taking advantage from the allergen exposure that occurs during the omPT for Ni.

METHODS

Thirty-seven symptomatic patients underwent to omPT for Ni. Before and after omPT, serum and urine Ni concentrations were determined by mass spectrometry, the white blood cells were counted by hemochromocytometric assay, the peripheral lymphocyte typing was carried out by flow cytometry, total IgE and cytokine serum concentrations were measured by immunoenzymatic assays. The local lymphocyte typing was performed by immunohistochemistry only after omPT.

RESULTS

According to the omPT outcomes, 25 patients were defined as Ni-sensitive and the remaining 12 as controls. After omPT, serum and urine Ni concentrations increased significantly in all patients, while a significant increment of circulating lymphocytes and neutrophils was highlighted, respectively, in Ni-sensitive and control patients. Consistently, the Th and Tc circulating lymphocytes, as well as the Th/Tc ratio increased significantly in Ni-sensitive patients after omPT. No noteworthy increment in serum concentrations of total IgE and selected cytokines was observed in any patient after omPT. The presence of CD3+, CD4+, and CD8+ cells was highlighted on the oral mucosa biopsy samples taken from Ni-sensitive patients after omPT.

CONCLUSIONS

In patients with ACM, a local adaptive response with increased lymphocyte trafficking appears to be the most likely mechanism of reaction to Ni administered with the omPT.

Recent progress in studies of metallic nickel and nickel-based nanoparticles' genotoxicity and carcinogenicity

Recently, nanoparticles have been the focus of many research and innovation. Metallic nickel and nickel-based nanoparticles are among those being exploited. Nickel fine particles are known to be genotoxic and carcinogenic. It has been discovered that many properties of nano sized elements and materials are not present in their bulk states. The nano size of these particles renders them the ability to be easily transported into biological systems, thus raising the question of their effects on the susceptible system. Therefore scientific research on the effects of nickel nanoparticles is important. This mini-review intends to summarize the current knowledge on the genotoxicity and carcinogenicity potential of metallic nickel and nickel-based nanoparticles implicated in in vitro and in vivo mammalian studies.

Genotoxicity and carcinogenicity of cobalt-, nickel- and copper-based nanoparticles

The nanotechnology industry has matured and expanded at a rapid pace in the last decade, leading to the research and development of nanomaterials with enormous potential. The largest source of these nanomaterials is the transitional metals. It has been revealed that numerous properties of these nano-sized elements are not present in their bulk states. The nano size of these particles means they are easily transported into biological systems, thus, raising the question of their effects on the susceptible systems. Although advances have been made and insights have been gained on the effect of transitional metals on susceptible biological systems, there still is much ground to be covered, particularly with respect to our knowledge on the genotoxic and carcinogenic effects. Therefore, this review intends to summarize the current knowledge on the genotoxic and carcinogenic potential of cobalt-, nickel- and copper-based nanoparticles indicated in in vitro and in vivo mammalian studies. In the present review, we briefly state the sources, use and exposure routes of these nanoparticles and summarize the current literature findings on their in vivo and in vitro genotoxic and carcinogenic effects. Due to the increasing evidence of their role in carcinogenicity, we have also included studies that have reported epigenetic factors, such as abnormal apoptosis, enhanced oxidative stress and pro-inflammatory effects involving these nanoparticles.

Allergic skin disease

The two most common allergic skin diseases in the world are often the least familiar to practicing surgeons: atopic dermatitis and contact dermatitis. When unrecognized, these disorders can cause great discomfort and decreased quality of life. This is only made worse by a surgical procedure which can exacerbate the disease process. Through proper recognition, management, and peri-surgical prophylaxis flares of these diseases can be avoided, leading to decreased morbidity and improved patient satisfaction. This article summarizes the pathophysiology and management of both atopic and contact dermatitis, with attention to implications for the surgeon.

Contact sensitivity to metals (chromium, cobalt and nickel) in childhood

Metals, especially nickel, are the most common contact allergens in children. Recent data has shown increased incidence of allergy in industrialized countries. Sensitization can occur at any age, even in neonates. Costume jewelry, particularly earrings, is linked to increased sensitization to nickel. Sensitization to cobalt often occurs by the use of costume jewelry. The most common source of sensitization to chromium is leather. Due to the absence of a specific therapy, the main treatment is to identify and avoid the responsible allergens. This article presents an updated view on the epidemiological and clinical aspects of contact allergy to metals, focusing on prevention strategies and risk factors, and warns about possible and new sources of contact.

Drug hypersensitivity and human leukocyte antigens of the major histocompatibility complex

The human leukocyte antigen (HLA) genes are the most polymorphic in the human genome and are critical in regulating specific immunity, hence their historical discovery as "immune response" genes. HLA allotypes are also implicated in unwanted immune reactions, including drug hypersensitivity syndrome, in which small therapeutic drugs interact with antigenic peptides to drive T cell responses restricted by host HLA. Abacavir, allo-purinol, and carbamazepine are three commonly used drugs that cause a T cell-mediated hypersensitivity that is HLA linked, with each drug exhibiting striking specificity for presentation by defined HLA allotypes. Recent findings have begun to unearth the mechanistic basis for these HLA associations, and here we review recent advances in the field of HLA-associated drug hypersensitivities.

Cellular phone and cellular phone accessory dermatitis due to nickel allergy: report of five cases

Cellular phone dermatitis, also known as mobile phone dermatitis, is a recently recognized condition due to either nickel or chromate allergy. Cellular phone dermatitis has most often been reported in young adults and less commonly in adolescents. We describe five adolescents whose cellular phone dermatitis was caused by nickel allergy.

Absorption of nickel, chromium, and iron by the root surface of primary molars covered with stainless steel crowns

Objective. The purpose of this study was to analyze the absorption of metal ions released from stainless steel crowns by root surface of primary molars. Study Design. Laboratory research: The study included 34 primary molars, exfoliated or extracted during routine dental treatment. 17 molars were covered with stainless-steel crowns for more than two years and compared to 17 intact primary molars. Chemical content of the mesial or distal root surface, 1 mm apically to the crown or the cemento-enamel junction (CEJ), was analyzed. An energy dispersive X-ray spectrometer (EDS) was used for chemical analysis. Results. Higher amounts of nickel, chromium, and iron (5-6 times) were found in the cementum of molars covered with stainless-steel crowns compared to intact molars. The differences between groups were highly significant (P < .001). Significance. Stainless-steel crowns release nickel, chromium, and iron in oral environment, and the ions are absorbed by the primary molars roots. The additional burden of allergenic metals should be reduced if possible.

Allergic skin diseases

The skin is one of the largest immunologic organs and is affected by both external and internal factors, as well as innate and adaptive immune responses. Many skin disorders, such as atopic dermatitis, contact dermatitis, urticaria, angioedema, psoriasis, and autoimmune blistering disorders, are immune mediated. Most of these diseases are chronic, inflammatory, and proliferative, in which both genetic and environmental factors play important roles. These immunologic mechanisms might have implications for potential targets of future therapeutic interventions.