The relevance of chlorhexidine contact allergy

Background. Chlorhexidine is used for disinfection of skin and mucosae in medicine and dentistry. Prolonged exposure may lead to contact sensitization and allergic contact dermatitis or stomatitis. Objectives. The purpose of this study was to analyse the sources of chlorhexidine exposure and sensitization, and to obtain data on the prevalence of sensitization and chlorhexidine‐related contact allergy. Patients and methods. From 1999, patch testing was performed with chlorhexidine digluconate (0.5% aq.) on 7610 general dermatology patients with suspected contact allergy at the Turku University Hospital Dermatology Department. The medical records were reviewed concerning the patients' exposure to chlorhexidine. Results. A positive patch reaction to chlorhexidine was seen in 36 patients (0.47%). Current dermatitis or stomatitis caused by chlorhexidine‐containing topical medicaments was seen in 5 patients. Chlorhexidine sensitization contributed to the current dermatitis in 11 patients. A history of earlier exposure to chlorhexidine‐containing products was recalled by only 16 sensitized patients, whereas no exposure was revealed in 4 cases. Conclusions. Chlorhexidine‐containing corticosteroid creams, skin disinfectants and oral hygiene products are principal sources of chlorhexidine contact sensitization. Exposure to chlorhexidine in cosmetics may lead to delayed improvement of eczema in sensitized patients, emphasizing the importance of identifying the potential cosmetic sources.     

Occupational allergic contact dermatitis and patch test results of leather workers at two Indonesian tanneries

Background. Tannery workers are at considerable risk of developing occupational contact dermatitis. Occupational skin diseases in tannery workers in newly industrialized countries have been reported, but neither the prevalence of occupational allergic contact dermatitis nor the skin‐sensitizing agents were specifically examined in those studies. Objectives. To assess the prevalence of occupational allergic contact dermatitis in Indonesian tanneries, identify the causative allergens, and propose a tannery work series of patch test allergens. Patients/methods A cross‐sectional study in all workers at two Indonesian tanneries was performed to assess the prevalence of occupational contact dermatitis via a questionnaire‐based interview and skin examination. Workers with occupational contact dermatitis were patch tested to identify the causative allergens. Results. Occupational contact dermatitis was suspected in 77 (16%) of the 472 workers. Thirteen (3%) of these 472 workers were confirmed to have occupational allergic contact dermatitis. Potassium dichromate (9.2%), N,N‐diphenylguanidine (5.3%), benzidine (3.9%) and sodium metabisulfite (2.6%) were found to be the occupationally relevant sensitizers. Conclusions. The sensitization pattern showed some differences from the data in studies reported from other newly industrial countries. We compiled a ‘tannery work series' of allergens for patch testing. A number of these allergens may also be considered for patch testing in patients with (leather) shoe dermatitis.     

A single accidental exposure may result in a chemical burn, primary sensitization and allergic contact dermatitis

It is known from experimental studies that antigenic potency and the concentration of antigen determine whether exposure to an antigen will result in sensitization. A single accidental exposure to concentrated antigen may therefore induce primary sensitization. The purpose of this report was to collect clinical cases in which a single exposure had resulted in contact dermatitis suspected to be allergic. Only patients without previous relevant skin symptoms were included. Patch testing was used to demonstrate sensitization. 6 patients developed occupational allergic contact dermatitis from accidental exposure. Patch testing revealed allergy to diglycidylether of bisphenol A epoxy resin, poly functional aziridine hardener, methyl acrylate, phenol-formaldehyde resin, and methylchloroisothiazolinone/methylisothiazolinone (Kathon LX), respectively. Furthermore, 2 patients developed allergic contact dermatitis from their first exposure to tear gas chemicals, namely omega-chloroacetophenone and ortho-chlorobenzylidene malonitrile. A single exposure can therefore induce both sensitization and subsequent allergic contact dermatitis without further exposure. The allergens described must be considered strong allergens. The skin should immediately be cleaned if an accidental splash with such an allergen has taken place.     

Anti‐hapten antibodies in response to skin sensitization

Whereas T lymphocyte (T cell) activation is the key event in the acquisition of skin sensitization and subsequent elicitation of allergic contact dermatitis, the humoral component of immune responses to organic contact allergens has received little consideration. There is evidence that, in experimental animals, topical exposure to potent contact allergens is associated with B cell activation and proliferation, and hapten‐specific antibody production. However, there is very limited evidence available for anti‐hapten antibody responses being induced following topical exposure of humans to contact allergens. Nevertheless, it is important to appreciate that there are almost no negative studies in which evidence for antibody production as the result of skin sensitization has been sought and not found. That is, there is absence of evidence rather than evidence of absence. Furthermore, exposure to chemical respiratory allergens, in which the skin has been implicated as a potential route of sensitization, results in anti‐hapten antibody responses. It is proposed that skin sensitization to contact allergens will normally be accompanied by antibody production. The phenomenon is worthy of investigation, as anti‐hapten antibodies could potentially influence and/or regulate the induction of skin sensitization. Moreover, such antibodies may provide an informative correlate of the extent to which sensitization has been acquired.     

Kontaktallergie und Atopie

Retrospective studies demonstrate that the prevalence of skin sensitization does not significantly differ between atopic and non-atopic patients. In children and adolescents the risk for sensitization seems to occur independently from AD. According to the results of a recent study, AD patients are overrepresented in the group of polysensitized patients. IgE-mediated sensitization as well as an early onset of AD and duration of the disease have been identified as possible risk factors for skin sensitization to contact allergens. A defective permeability barrier with increased epidermal water loss is a hallmark of AD and contributes to sensitization against common allergens. A highly significant association between FLG mutations and the risk of early onset, severe, persistent AD and an increased risk for asthma has been shown in several studies. A more recent study revealed an association between FLG mutations and increased nickel sensitization, but not other contact allergens. However, further large prospective studies with well-characterized patients are necessary to clarify the correlation between impaired skin barrier, atopic dermatitis and allergic contact dermatitis.     

Anogenital allergic contact dermatitis, the role of spices and flavour allergy

Background: In patients with vulval or anogenital dermatitis, irritant contact dermatitis is more common than allergic contact dermatitis. The reported frequency and relevance of contact sensitivity in anogenital dermatitis varies greatly. Objective: To determine the frequency and relevance of contact sensitization in a Dutch group of female patients with chronic anogenital complaints. Methods: We reviewed patch test results of 53 women with chronic anogenital complaints, with sole vulval symptoms in 29 women and sole perianal in 5, in whom inflammatory skin diseases like lichen sclerosus, lichen planus, psoriasis, as well as infectious diseases were unlikely or excluded as a cause of their symptoms. All women were tested with the European baseline series plus additional test series according to their personal history. Results: Thirty‐five patients (66%) showed one or more positive test reactions. Seven of these patients (20%) had one or more clinically relevant positive reactions, most often to flavours and spices. Conclusion: A considerable number of patients with anogenital dermatitis have a contact sensitization. Clinically relevant reactions were mainly found to spices and flavours. This is in contrast to the data reported in the literature that shows most contact allergies in vulval patients to ingredients of topical medication.     

Contact dermatitis to para‐phenylenediamine in hair dye following sensitization to black henna tattoos – an ongoing problem

Summary Background: The increased frequency of case reports of allergic contact dermatitis from non‐permanent black henna tattoos in recent years shows the popularity of this form of body painting. Patients and methods: Seven patients presented with allergic contact dermatitis after initial hair or eyelash dyeing. They all had a history of a previous reaction from a black henna tattoo. All were patch tested with the European standard patch test series and the standard supplemental series, as well as special series for dyes and hairdressers. Results: All seven patients showed a positive reaction in patch testing with para‐phenylenediamine (PPD) (0.3 % and/or 1.0 % in pet.). Five patients also had positive reactions to other dyes such as aminophenol, para‐toluene diamine, disperse orange and yellow and four patients reacted to benzocaine. These were interpreted as cross‐reactions. The time from sensitization by the black henna tattoo to the onset of allergic contact dermatitis after hair dyeing was an average of 6.2 years. Conclusions: The most common cause of allergic contact dermatitis after black henna tattoos is PPD. Both the long skin contact and the high concentrations of PPD increase the risk of sensitization. Allergic contact dermatitis may be followed by post‐inflammatory hyper‐ or hypopigmentation, scarring and lifelong sensitization, which can have occupational impact, especially for hair dressers and cosmeticians.     

Tertiäre Prävention von Berufsdermatosen

Background: Inpatient tertiary prevention of occupational skin diseases is indicated when the employee is threatened with loosing their job. Earlier studies have shown that with intensive tertiary preventive measures, 2/3 of such individuals can continue their jobs long‐term. Data on the effectiveness of tertiary prevention for various occupational groups has not been previously available. Patients and Methods: The outcome of all participants treated in the year 2002 was analyzed according to occupational groups with respect to diagnosis, medical intervention prior and during the inpatient period. Results: In 91 % of 296 cases contact dermatitis of the hands was diagnosed (75 % primary irritant contact dermatitis (37 % chronic irritant contact dermatitis, 38 % irritated atopic hand eczema, 16 % allergic contact dermatitis). Clinically relevant Type IV‐delayed hypersensitivity (allergic contact dermatitis) reactions were identified in 42 % of cases; in most cases, the delayed hypersensitivity followed irritant contact dermatitis. In more than 83 % of cases, a complete or nearly complete remission was achieved. Clinical relevant Type IV sensitization was most frequent in hairdressers (66 %). Cleaning and housekeeping personnel most frequently used corticosteroids on a regular basis (60 %) and most often experienced corticosteroid withdrawal (53 %) and atrophy of the skin of the hands (23 %). Conclusion: The data from studies on the tertiary prevention of occupational skin diseases reveal strategies for the optimization of outpatient care indicate specific occupational risk factors. The variance between professions may reflect differing approaches to secondary prevention.     

Dermatoses in metal workers

In an epidemiological study of 286 metalworkers exposed to metalworking fluids (MWF), the prevalence of skin problems was investigated. Minor changes, such as a dry rough skin with slight erythema, were seen in 31%, and major changes, such as more serious and widespread dermatitis, were observed in 27% of all workers. By far the most cases were of irritant origin; in only 2.8% was a contact sensitization established. Exposure to water-based MWF caused irritant contact dermatitis more often than exposure to neat oils. No influence was found of the presence of atopy on the occurrence of dermatitis. Other factors that may result in irritation of the skin are discussed, as well as measures to be taken to minimize insult of the skin.     

Contact dermatitis

Contact dermatitis is a common skin disease caused by contact with irritants or allergens. Irritant contact dermatitis is a result of nonspecific irritant factors, which cause activation of mainly innate immunity, resulting in skin inflammation. Contact hypersensitivity, which manifests itself as allergic contact dermatitis, is result of adaptive immune response, where sensitization to hapten-carrier complexes leads to T-cell-mediated contact allergy. Subsequent contact with the hapten results in skin inflammation. This review concentrates on the role of cutaneous receptors in contact dermatitis and highlights potential targets for treatment interventions.     

Epidemiología de la dermatitis de contacto: prevalencia de sensibilización a diferentes alérgenos y factores asociados

BackgroundIn clinical practice, contact dermatitis is a relatively common skin complaint, whose prevalence has increased in recent years. Study by patch testing is essential for diagnosis of contact sensitization.ObjectivesTo study the prevalence of sensitization to different allergens in a standard battery and observe the influence of different epidemiological and clinical variables on contact sensitization. A large number of allergens were included in our battery in order to detect new sensitizations whose prevalence might justify further study.Material and methodsThis was a retrospective, observational, epidemiological study of 1092 patients, conducted in our skin allergy unit between January 1, 2000, and December 31, 2005. All patients were studied with a battery of 51 allergens. We assessed the following variables: sex, age, type of referral, occupation, site and course of skin lesions, personal and family history of atopy, positive patch tests, clinical significance, diagnosis, source of sensitization, and occupational relationship.ResultsAt least 1 positive result was found in 55% of the patients, and 55.7% presented atopic dermatitis in one of its clinical variants: allergic contact dermatitis (28.2%), irritant contact dermatitis (20.1%), photoallergic contact dermatitis (2.2%), and phototoxic contact dermatitis (1.2%). The most prevalent allergens were nickel sulfate (29.3%), palladium chloride (11.7%), cobalt chloride (10.8%), potassium dichromate (7.5%), fragrance blends (6.3%), and p-phenylenediamine (6.1%).A positive occupational relationship was found in 41.1%, and 21.3% of the patients studied were diagnosed with occupational contact dermatitis. Metalworkers, construction workers, and professional hairdressers were the most strongly represented groups. The most common source of sensitization was contact with metallic objects, followed by drugs, cosmetics, and rubber items. Female sex was the only independent variable that had a significant influence on the risk of contact sensitization in general.ConclusionWomen became sensitized at a younger age than men, and the frequency of positive results in the patch tests increased with age, reaching a maximum at between 60 and 69 years of age, when the greatest rate of sensitization occurred. Comparison of our results with other Spanish data showed a progressive and constant increase in sensitization to nickel sulfate, fragrance blends, balsam of Peru, and rosin, and a decrease in sensitization to potassium dichromate. The inclusion of new allergens such as palladium chloride, diallyl disulfide, and p-toluene sulfonamide formaldehyde improved the sensitivity of the standard battery in the detection of contact sensitization. We therefore recommend further studies of these allergens.     

Sodium metabisulfite as a contact allergen--an example of a rare chemical mechanism for protein modification

Background. Skin‐sensitizing chemicals that cause allergic contact dermatitis do so by reacting with self‐proteins such that the modified structure becomes antigenic. The reaction chemistry involved is well characterized, but there are exceptions, such as the occasional allergen sodium metabisulfite. Objectives. To identify the potential in cutaneo reaction chemistry of sodium metabisulfite. Methods. The established protein reaction chemistry associated with aqueous sulfite chemistry was explored in the context of the protein modification stage in allergic contact dermatitis. Results. A probable mechanism for the in cutaneo modification of proteins by sodium metabisulfite involves the sulfite di‐anion, acting as a nucleophile towards electrophilic centres in proteins, which is a rare mechanism, as most known skin‐sensitizing chemicals behave as electrophiles. Conclusions. Sodium metabisulfite is an unusual but not infrequent contact allergen whose chemistry suggests a previously unrecognized protein modification mechanism involving nucleophilic attack by sulfite di‐anions on target electrophilic centres in skin proteins. The chemical properties required for sensitization by nucleophilic attack on skin proteins are quite restrictive, so the domain of nucleophilic sensitizers is expected to be small. Thiourea derivatives are among the sensitizers likely to act by this mechanism.     

Dermatitis in bulb growers

A damaged skin forms a health hazard in flower-bulb growers as it enables higher permeation rates For pesticides than normal skin. Therefore, an investigation was performed into the skin condition of 103 bulb growers and 49 controls. Contact dermatitis of the hands was of the same order (11 and 10%) in both groups. However, minor signs of dermatitis were seen more often in bulb growers (30 versus 8%, p <0.05). Most growers had contact with narcissus sap during the investigation. This irritant sap, as well as many other skin contacts with irritants such as hyacinth dust and pesticides, seemed to be responsible for many skin complaints. Contact serialization was suspected in 19 growers and 3 controls. Patch tests showed that contact sensitization existed to pesticides in probably 10, and to flower-bulb extracts in 4 growers. Reactions to propachlor were not regarded as very reliable as the test concentration seemed to be marginally irritant. There were only a few allergic reactions to narcissus (3) and tulip (2) and none to hyacinth. This investigation showed that minor irritant contact dermatitis was frequent in bulb growers, and indicated that contact sensitization to pesticides and bulbs seemed to be a less frequent but important cause of dermatitis.     

Textile dye allergic contact dermatitis following paraphenylenediamine sensitization from a temporary tattoo

Textile dye allergy is frequently caused by azo dyes, which can cross-react with structurally similar compounds, including paraphenylenediamine. A case of allergic contact dermatitis to azo textile dyes, presenting principally as a sock dermatitis, is presented. The patient also gave a history of an episode of scalp dermatitis consistent with contact allergy to paraphenylenediamine in hair dye. It is proposed that paraphenylenediamine sensitization from a temporary skin tattoo may have been the primary sensitizing event for these reactions.     

Contact sensitization to common haptens is associated with atopic dermatitis: new insight

Background It has been much debated whether atopic dermatitis (AD) is associated with contact sensitization as past findings have been conflicting. A positive association might change our clinical practice. Objectives To investigate the association between AD and contact sensitization taking the likely route of allergen exposure into account. Methods Questionnaire and clinical data from a cross‐sectional study performed in a general population in Copenhagen. In total, 3202 adults aged 18–69 years were patch tested, filaggrin genotyped for 2282del4 and R501X and questioned about AD. Results The variable ‘contact sensitization to at least one allergen, but not nickel and thimerosal’ was significantly associated with AD (odds ratio 2·53, 95% confidence interval 1·59–4·04). The higher prevalence of contact sensitization was driven mainly by fragrance chemicals. In a subanalysis in nonpierced women, a positive association was also found for nickel sensitization. Nickel and thimerosal sensitization may introduce bias in data analysis as these allergies often develop following skin piercing where the skin compartments are bypassed. Conclusions We suspect that individuals with self‐reported AD from this study mainly had mild disease. However, clinicians should be aware of increased levels of contact sensitization in individuals with AD. Patch testing should therefore be considered at an early point in individuals with a history of AD and active disease. The fundamental relationship between atopic disease and environmental chemical exposure may be of a more complex and intimate nature than previously supposed.     

Filaggrin mutations are strongly associated with contact sensitization in individuals with dermatitis

Background. Although heterozygous filaggrin gene (FLG) mutation carriers seem to have an increased risk of atopic, irritant and allergic nickel dermatitis, it remains unclear whether the risk of contact sensitization to allergens other than nickel is also elevated in FLG mutation carriers. Objectives. We hypothesized that heterozygous FLG mutation carriers who suffer from dermatitis will have strongly reduced or even absent filaggrin levels during episodes of inflammation, potentially increasing the penetration of contact allergens, and hence the risk of becoming sensitized. Materials and methods. During 2006–2008, 3335 randomly invited 18–69‐year‐old adult Danes participated in a general health examination, filled out a questionnaire, and were genotyped for the R501X and 2282del4 mutations in FLG. Results. A logistic regression analysis restricted to individuals who reported atopic dermatitis and frequent episodes of hand eczema showed a strong association between FLG mutations and contact sensitization to allergens other than nickel (odds ratio 5.71; 95% confidence interval 1.31–24.94). In participants without dermatitis, no association was found between contact sensitization and FLG mutations. Conclusion. FLG mutation carriers with self‐reported dermatitis have an increased risk of contact sensitization to substances other than nickel, whereas FLG mutations alone may not, or may only slightly, increase the risk of sensitization.     

Contact dermatitis from a presumed allergy to paraphenylenediamine

Paraphenylenediamine (PPD) is a potent skin allergen found in permanent hair dye and temporary henna tattoo ink. Several cases of adverse skin reactions to PPD have been reported in the literature. Here we present a case involving a patient who acquired a temporary tattoo while vacationing in Mexico and subsequently developed contact dermatitis at the tattoo site. He provided a history of permanent hair dye use in the past with associated cutaneous reaction. Temporary tattoos have become increasingly popular with travelers and as a result so have reports of associated allergic contact dermatitis. Of concern is cross‐reaction of PPD to related compounds, severe reactions in younger populations and sequelae including increased sensitization, permanent scarring, and persistent postinflammatory hyperpigmentation.     

Hand dermatitis as an unsuspected presentation of textile dye contact sensitivity

The aim of this study was to evaluate disperse dye sensitization in patients with hand dermatitis. From January 1996 to December 2000, we identified 130 patients with hand dermatitis reacting to one of the 7 dyes included in our standard series. In 82 subjects the dermatitis was localized to the hands alone, whereas 48 patients had lesions both on the hands and on other skin sites. Disperse Blue dyes, and Disperse Orange 3 were the most common sensitizers. Among the 13 subjects allergic to disperse dyes alone, we found 3 cases of occupational allergic contact dermatitis, 1 child with atopic dermatitis worsening after the use of synthetic fibre garments, 4 subjects affected by clothing dermatitis, and 5 individuals occupationally exposed to irritants with a dermatitis involving the hands alone. In the latter, the hands may represent a 'locus minoris resistentiae', and both induction and elicitation of contact sensitization could be caused by impaired barrier function at a skin site repeatedly exposed to sensitizing garments.     

Occupational food-related hand dermatoses seen over a 10-year period

Background. Protein contact dermatitis was originally defined in 1976 by Hjorth and Roed‐Petersen as a distinct kind of dermatitis seen in patients with occupational food contact. Even though occupational skin diseases are frequent in Denmark, little attention has been paid to protein contact dermatitis, and the frequency is unknown. Objectives. To evaluate the frequency of occupational food‐related hand dermatoses and test results in patients occupationally exposed to foods. Materials and Methods. This was a retrospective study based on examinations, including skin prick testing and patch testing, performed at the Department of Dermato‐Allergology, Gentofte University Hospital, Denmark between 2001 and 2010. Results. Of all patients (n = 372), 57.0% had irritant contact dermatitis, 22.0% had protein contact dermatitis, 2.4% had contact urticaria, and 1.8% had allergic contact dermatitis. A suggestion for diagnostic criteria is presented. Frequent risk occupations were cooking in restaurants, baking, and kitchen work. Substantially more patients reacted in skin prick testing with fresh foods than with food extracts. Conclusion. Protein contact dermatitis is a frequent disorder among patients who professionally handle foods, and should be considered to be a distinct clinical entity. When diagnosing protein contact dermatitis and in other food‐related skin prick testing procedures, it is important to include fresh foods.