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The exposure of dental personnel to airborne methacrylates and natural rubber latex (NRL) allergens was studied during placing of composite resin restorations in six dental clinics in Finland. Both area and personal sampling were performed, and special attention was paid to measurement of short-term emissions from the patient's mouth. Methacrylates were collected onto thermal desorption tubes filled with Tenax TA and NRL allergens onto membrane filters. The methacrylate samples were thermally desorbed and analysed by gas chromatography with mass selective detection. The NRL allergen concentrations were determined by the allergen-specific IgE-ELISA-inhibition method. The median concentration of 2-hydroxyethylmethacrylate (2-HEMA) was 0.004 mg m-3 close to the dental nurse's work-desk and 0.003 mg m-3 in the breathing zone of the nurse with a maximum concentration of 0.033 mg m-3. Above the patient's mouth the concentration of 2-HEMA was about 0.01 mg m-3 during both working stages, i.e., during application of adhesive and composite resins and during finishing and polishing of the fillings. Maximum concentrations of 3-5 times higher than median concentrations were also measured. Triethyleneglycol dimethacrylate was released into the air mainly during the removal of old composite resin restorations (0.05 mg m-3) and only to a minor extent during finishing and polishing procedures. The median concentration of the NRL allergen was 0.12 au m-3 (au = arbitrary unit) with a maximum concentration of 1.1 au m-3. The results show that, except for short-term emissions from the patient's mouth, the exposure of dental personnel to methacrylates and NRL allergens is very low. Measures to reduce exposure are discussed, as the airborne concentrations of methacrylates should be kept as low as possible in order to reduce the risk of hypersensitivity.

Background: Dental products contain many allergens, and may cause problems both for patients undergoing dental treatment and for dental personnel because of occupational exposure. Individual patch test clinics may not study sufficient numbers of patients to collect reliable data on uncommon allergens., Objective: To collect information on dental allergens based on a multicenter study., Materials and Methods: The Finnish Contact Dermatitis Group tested more than 4,000 patients (for most allergens, 2,300 to 2,600 patients) with dental screening series. Conventional patch testing was performed. The total number and percentage of irritant (scored as irritant [IR] or doubtful [?]) and allergic (scored as +, ++, or +++) patch test reactions, respectively, were calculated, as well as the highest and lowest percentage of allergic patch test reactions recorded by the different patch test clinics. A reaction index (RI) was calculated, giving information on the irritancy of the patch test substances., Results: The most frequent allergic patch test reactions were caused by nickel (14.6%), ammoniated mercury (13%), mercury (10.3%), gold (7.7%), benzoic acid (4.3%), palladium (4.2%) and cobalt (4.1%). 2-hydroxyethyl methacrylate (2.8%) provoked most of the reactions caused by (meth)acrylates. Menthol, peppermint oil, ammonium tetrachloroplatinate, and amalgam alloying metals provoked no (neither allergic nor irritant) patch test reactions., Conclusion: Patch testing with allergens in the dental screening series, including (meth)acrylates and mercury, needs to be performed to detect contact allergy to dental products., (Copyright 2001 by W.B. Saunders Company.)

Background: Compositae mix and sesquiterpene-lactone (SL) mix are important patch test substances to show allergic contact dermatitis from various Compositae plants., Objectives: The aims of this study are to calculate the sensitization rates to Compositae mix and SL mix in an occupational dermatology clinic and to describe cases of active sensitization caused by patch testing with Compositae mix and SL mix., Methods: Conventional patch testing was performed. SL mix (0.1%) and Compositae mix (6% in petrolatum) were tested in a modified European standard series and a plant allergen series. Testing with other appropriate patch test series was also performed., Results: SL mix provoked 8 allergic patch test reactions (0.7%) in 1,076 patients, whereas Compositae mix was positive in 15 of 346 patients (4.2%). Three patients were actively sensitized to Compositae mix and 1 patient to SL mix. One patient was also sensitized to other plant allergens in a series of allergenic plant chemicals, namely to Mansonone A, an ortho-quinone; (R)-3,4-dimethoxydalbergione, a quinone; and Chlorophorin, a hydroxy stilbene. Allergic patch test reactions to laurel leaf were caused by cross-sensitization to SLs., Conclusion: Compositae mix seems to be a more important patch test substance than SL mix to detect allergic contact dermatitis to Compositae plants, but patch testing may sensitize. The concentration of the individual components of the Compositae mix should be adjusted so that the mix detects allergic patients but does not sensitize., (Copyright 2001 by W.B. Saunders Company)

Patch testing is the predominant method of establishing contact allergy. The present patch test technique is the result of a continuous process of development and improvement since its first application in the late 19th century. The perfect patch test should give no false-positive and no false-negative reactions. The ideal patch test should also cause as few adverse reactions as possible, particularly no patch test sensitization. Even though the history and examination of a patient with suspected allergic contact dermatitis will give clues to possible sensitizers, it is not sufficient to patch test only with initially suspected sensitizers; unsuspected sensitizers used for patch testing frequently turn out to be the real cause of the dermatitis. Fortunately, a small number of substances are considered to account for the majority of delayed hypersensitivity reactions. Therefore, generally 20-25 test preparations consisting of chemically defined compounds, mixes of allergens, and natural and synthetic compounds, are grouped into a standard test series. The requirements to be fulfilled by a sensitizer in a standard patch test series are discussed in this article. A procedure of investigations is proposed before a sensitizer is included in a standard series.

Statistics on 10 years of patch testing with 30 (meth)acrylates were compiled. Altogether 275 patients were patch tested and 48 patients (17.5%) had an allergic reaction to at least 1 (meth)acrylate. The (meth)acrylates most often provoking an allergic patch test reaction were 2-hydroxyethyl acrylate (2-HEA; 12.1%), 2-hydroxypropyl methacrylate (2-HPMA; 12.0%) and 2-hydroxyethyl methacrylate (2-HEMA; 11.4%). No allergic reactions were caused by 2-ethylhexyl acrylate (2-EHA), 2,2-bis[4-(methacryloxy)phenyl]propane (BIS-MA), trimethylolpropane triacrylate (TMPTA), oligotriacrylate 480 (OTA 480), N,N-methylenebisacrylamide (MBAA), or ethyl cyanoacrylate (ECA). The frequency of allergic patch test reactions presented cannot be considered as a "ranking" list of the most sensitizing (meth)acrylate compounds. In order to be able to judge the sensitization capacity of various (meth)acrylate compounds in humans, it would be necessary to have detailed information on the exposure history of the patients studied, including the purity of the (meth)acrylate compounds. Currently, this is not possible because (meth)acrylate-containing products regularly contain undeclared (meth)acrylate compounds.

It has been known since the 1940s that nail polishes contain allergenic ingredients. The aim of this study was to clarify whether the nail polishes on the market today contain significant amounts of allergens, and what the solvents are. The following ingredients were determined: toluene, toluene sulfonamide formaldehyde resins, free formaldehyde, acrylates, methacrylates and certain organic solvents. The study comprised 20 brands and 42 samples. All the nail polishes analysed contained allergenic toluene sulfonamide formaldehyde resins (TSFR), in concentrations from 0.08 to 11.0%. The concentration of total formaldehyde varied from 0.02% to 0.5%. The more TSFR a nail polish contained, the higher was its formaldehyde content. Probably not only TSFR-allergic but also formaldehyde-allergic persons may get dermatitis from many of the nail polishes studied. The concentrations of acrylates and methacrylates were so small that they are of practical significance only to those previously sensitized to acrylates. Of the organic solvents, toluene was still widely used, whereas xylene was found in only 1 product. The nail polishes on the market today are not safe for all consumers. However, according to the regulations of the European Union, the packaging labeling of all cosmetic products must be supplied with a list of ingredients from the beginning of 1998. This will help the consumer to avoid allergenic products. A better alternative could, however, be to substitute the most allergenic ingredients with substances possessing minor allergy potency.

Background: Cow dander is the most common cause of occupational contact urticaria in Finland. Occasionally cow dander also causes allergic contact dermatitis, which can be revealed by patch testing with cow dander., Objective: A patient with a combined type I and type IV allergy to cow dander is the subject of this report., Results: She had intense pruritus, whealing, and severe dermatitis, but no respiratory symptoms. Skin tests and radioallergosorbent test indicated that she had both type I and type IV allergy to cow dander., Conclusion: Increasing numbers of cases with both type I and type IV allergy are reported, but the mechanism is not clear. In our clinic, we classify immediate reactions as contact urticaria if the clinical picture involves whealing, and as protein contact dermatitis if dermatitis dominates the clinical picture. If delayed allergic patch test results are obtained, we consider it allergic contact dermatitis.

Epoxy resin compounds (ERC) include a large number of chemicals, such as epoxy resins (ER), reactive diluents and hardeners. Many hardeners, e.g., aliphatic polyamines, are well-known sensitizers. Another type of ER hardeners are the phthalic anhydrides, such as methylhexahydrophthalic anhydride (MHHPA) and methyltetrahydrophthalic anhydride (MTHPA), which have been reported as causing immunologically-mediated respiratory diseases and contact urticaria, but not allergic contact dermatitis. Here, we present a horizontal boring-machine worker who developed allergic contact dermatitis, as well as allergic rhinitis and an immediate contact skin reaction from MHHPA. Patch testing with a dilution series of MHHPA in pet. elicited the following results: 2%, 1% and 0.5%, +2; 0.25% and 0.125%, + (3- to 6-day readings). An immunohistochemical and electron microscopic study also indicated that the patch test reactions were conventional-delayed allergic reactions. Interleukin 8 was observed in the epidermal cells, whereas interleukin 4 immunoreactivity was detected in the dermal cells. Immunoreactivity to-interleukin 5, granulocyte/macrophage-colophony stimulating factor (GM-CSF) or eosinophil cationic protein was not seen. In conclusion, the patient developed both Type I and Type IV allergy to MHHPA. The clinical data, patch test results, immunohistochemical and electron microscopic observations indicated that the MHHPA allergy detected by the patch test reaction was a conventional delayed-type hypersensitivity reaction. The patient also had an allergic patch test reaction to para-phenylenediamine and diaminodiphenylmethane, possibly representing occupational sensitization.

Hairdressers are exposed daily at their work to many different hair chemicals and dandruff. The work-related nasal symptoms are common, especially with hair bleaching and striping. There are some reports on hairdressers asthma, but publications concerning occupational rhinitis among hairdressers are very few. The purpose of this study is to investigate the work-related rhinitis symptoms of hairdressers, and to study whether nasal provocation tests (NPTs) can be applied in diagnostics. The study subjects were 40 hairdressers having work-related rhinitis symptoms. Detailed work and exposure histories and work-related symptoms were inquired of using a questionnaire. Prick tests were done. Altogether 142 NPTs were done: 40 placebo, 36 dandruff, 35 ammonium persulphate (APS), and 31 ammonium thioglycolate (ATG). To register the nasal response rhinorrhea and nasal blockage were scored. In 3 allergen NPTs there was an essential change in the nasal status: in 2 APS and in 1 dandruff tests. Three patients were diagnosed as having an occupational rhinitis. The low number of positive reactions in NPTs and few positive reactions in skin prick tests verified that immediate allergy caused by hairdressers' work substances is uncommon. However, in cases of clear work-related rhinitis, there is a need to perform examinations to find the probable allergy.

The present study summarizes information on toothpaste composition as supplied by the manufacturers. The survey covered 48 items, virtually all toothpastes offered for sale in Finland. It was concluded that the toothpastes are not entirely safe to use, because almost 50% of the products studied contained a total of some 30 compounds widely recognized as allergens. According to the literature, the most common allergens in toothpastes are flavours (e.g., cinnamic aldehyde, cinnamon oil and peppermint) and preservatives. Symptoms include stomatitis, cheilitis, glossitis, gingivitis, perioral dermatitis and immediate hypersensitivity.

Coconut diethanolamide (CDEA), manufactured from coconut oil, is widely used as a surface-active agent in hand gels, hand-washing liquids, shampoos and dish-washing liquids. CDEA has rarely caused allergic contact dermatitis. During 1985-1992, we investigated 6 patients with occupational allergic contact dermatitis caused by CDEA. 2 became sensitized from a barrier cream, 3 from a hand-washing liquid, and 1 had been exposed both to a hand-washing liquid and to a metalworking fluid containing CDEA. Leave-on products (hand-protection foams) caused sensitization much more rapidly (2-3 months) than rinse-off products (hand-washing liquids; 5-7 years). Due to the extensive use of CDEA and the lack of proper declaration of products, it is difficult to avoid CDEA exposure. No contact allergy to another coconut-oil-derived sensitizer (cocamidopropyl betaine) was found in the patients.

Dental personnel are exposed to many sensitizing compounds at work and often develop multiple delayed allergies. Here we report on a dentist who got sensitized to several products that have not, or only seldom, caused sensitization earlier. These products were: coconut diethanolamide from her handwashing liquids, N-ethyl-4-toluene sulfonamide, a resin carrier in dental materials for isolating cavities underneath restorations, and 4-tolyldiethanolamine, an accelerator for inducing polymerization of dental acrylic resins at room temperature. The patient also had allergic patch test reactions to formaldehyde, phenol-formaldehyde resin, fragrance mix, and lauryl monoethanolamide, possibly from occupational exposure.

A long-lasting allergic patch test is a "normal" allergic patch test that remains positive for weeks or months. An immunohistochemical study of immunocompetent cells in the skin in this rare type of patch tests was performed. Most inflammatory cells were T11 positive T-lymphocytes. The majority of these cells were of the helper/inducer phenotype (T4+), but a relative increase of T8+ cells as compared to the initial (1-2d) stages of allergic patch tests was observed. T6+ Langerhans' cells (LCs) were normal or increased in number in the epidermis, while very few dendritic cells displayed Ial antigen in the epidermis, indicating loss of Ial-staining of LCs. High to very high numbers of T6+ cells were found in the dermis. An inflammatory reaction of hair follicles with moderate numbers of T6+ cells in the peribulbar infiltrate was observed indicating that hair follicles might act as shunt pathways for allergens. A defect in down regulation of the contact hypersensitivity reaction and/or a constant antigen stimulation could be responsible for the long-lasting allergic patch tests.