Contact dermatitis caused by airborne agents. A review and case reports

A general review is given of airborne-induced contact dermatoses, particularly of the irritant and allergenic types. Because the reports in the literature often omit the term airborne, 12 volumes of Contact Dermatitis (January 1975-July 1985) were screened, and the cases cited were classified in function of the anamnesis, lesion locations, causative irritants and allergens, and other factors. The present article also discusses differential diagnoses, in particular with regard to contact dermatitis of the face, ears, and neck. Finally, seven case reports of occupational and nonoccupational contact dermatitis problems caused by airborne agents are presented. In some of the cases the allergens have not been mentioned in published literature previously.

Occupational rubber glove allergy: results of the Information Network of Departments of Dermatology (IVDK), 1995-2001

About 21% of the patients with occupational contact dermatitis registered in the Information Network of Departments of Dermatology (IVDK) in the years 1995-2001 were patch tested due to suspected rubber glove allergy. We analysed reaction frequencies to thiurams, dithiocarbamates, mercaptobenzothiazole (MBT) and its derivatives, thioureas, and 1,3-diphenylguanidine (1,3-DPG). Thiurams were by far the most frequent rubber allergens in these patients (16.2% positive reactions, age- and sex-standardized), and the reaction frequency showed a decline from 20.9% in 1997 to 12.8% in 2000. However, this trend was not statistically significant, and was followed by an increase to 16.5% in 2001. All other rubber allergens showed no time trend at all. Although, according to manufacturers' information, the use of dithiocarbamates and MBT derivatives in rubber glove production increased in recent years, these allergens elicited positive reactions in only about 3% of the patients tested, and showed no increasing trend. Thioureas and 1,3-DPG are not widely used in rubber glove production, and play only a minor role in rubber glove contact allergy. Most of the positive reactions to 1,3-DPG are probably false-positive, irritant reactions.

Contact allergy and hand eczema in Swedish dentists

Hand eczema and contact allergy in Swedish dentists were studied in a multidisciplinary project. The aims of the study were to establish diagnoses, to investigate the occurrence of contact allergy, in particular to (meth)acrylates, and to evaluate certain consequences of hand eczema. A postal questionnaire on skin symptoms, atopy and occupational experience was mailed to 3,500 dentists aged <65 years, and licensed 1965-1995. The response rate was 88%. Among dentists living in 3 major cities, 14.9% (n= 191) reported hand eczema during the previous year. They were invited to a clinical examination, including patch testing with a standard and a dental series. 158/191 (83%) dentists attended, and hand eczema diagnosis was confirmed in 149/158 (94%). Irritant contact dermatitis was diagnosed in 67% and allergic contact dermatitis in 28%. On patch testing, 50% presented at least 1 positive reaction. The most frequent allergens were nickel sulfate, fragrance mix, gold sodium thiosulfate and thiuram mix. 7 (5%) had positive reactions to (meth)acrylates, all to 2-hydroxyethyl methacrylate and 6 also to ethyleneglycol dimethacrylate. 38% had consulted a physician, 4% had been on sick-leave and 1% had changed occupational tasks due to hand eczema. No dentist with allergy to acrylates had been on sick-leave or changed occupation. It is concluded that dentistry is a high-risk occupation for hand eczema, and that irritant contact dermatitis is most common. The prevalence of contact allergy to acrylates was below 1% in the population of responding dentists, and in most cases did not have serious medical, social or occupational consequences.

The frequency of contact sensitivity in North America 1972-74

Three thousand subjects in North America were patch-tested with 19 allergens. The most frequent sensitizers observed include nickel sulfate, caine mixture, potassium dichromate, balsam of Peru, thimerosal, ethylenediamine hydrochloride, paraphenylenediamine and thiram. The prevalence data compared with an earlier study indicates that the initial allergens reported warrant their continued inclusion in a routine patch test screening series in North America.

Changing frequency of thiuram allergy in healthcare workers with hand dermatitis

BACKGROUND

Healthcare workers (clinical, allied/paramedical professions and ancillary workers) may have prolonged contact with natural rubber latex devices, particularly in the form of natural rubber latex gloves.

OBJECTIVES

To examine the changing frequency of type IV thiuram allergy in healthcare workers with hand dermatitis over a 16-year period.

METHODS

During the study period, 450 healthcare workers (352 women and 98 men) with hand dermatitis were investigated, and their patch test results were analysed retrospectively.

RESULTS

On average, a thiuram-positive patch test was noted in 12% of individuals, with a peak incidence of 27% of the patients patch tested in 1994. Comparison of results between 1983--88 and 1989--93 showed a statistically significant increase in the incidence of thiuram-positive patch tests (odds ratio 2.55, 95% confidence interval 1.25--5.20, P = 0.01).

CONCLUSIONS

We have documented a changing frequency of thiuram-positive patch tests in healthcare workers with hand dermatitis since 1983. This may reflect changes in degree of exposure to thiurams in medical gloves during this period.

Release of thiurams and carbamates from rubber gloves

A method for quantitative determination of thiuram and carbamate derivatives released from rubber gloves into synthetic sweat is presented. The analysis was based upon determination of ester derivatives using gas-chromatography/mass spectrometry and isotope-dilution. The detection limit was 0.1 mg thiuram/carbamate in 200 ml synthetic sweat (0.5 ppm). The release of thiurams and carbamates from 5 household and 5 surgical types of gloves into synthetic sweat was determined. Each of the natural rubber gloves released varying amounts of thiurams (0-4.3 mg) as well as carbamates (0-8.1 mg). 22 thiuram-sensitized patients were patch tested with pieces of the gloves. Gloves releasing considerable amounts of thiurams and/or carbamates seemed to cause more positive patch test reactions in these patients than gloves releasing smaller amounts. Surgical gloves made from natural rubber caused a substantial larger number of positive patch test reactions than household gloves made from natural rubber. The amounts released per cm2 of the gloves were of the same order of magnitude as the content per cm2 patch test of thiuram mix, diluted 1:10. The accessibility of a quantitative, chemical analysis for thiurams and carbamates released from rubber gloves makes it reasonable to ask for declarations of rubber gloves. Proposals for threshold values for release of thiurams and carbamates from rubber gloves may be given in the future.

Occupational hand dermatitis in a tertiary referral dermatology clinic in Taipei

Occupational skin disease is one of the most common occupational diseases. The hand is the most frequent site of involvement in occupational skin disease. We interviewed and examined patients seen in the Contact Dermatitis Clinic of the National Taiwan University Medical Center, a tertiary referral center in Taipei City. For patients suspected of having allergic skin diseases, patch testing was carried out using the European standard series and suspected allergens. Occupational hand dermatitis (OHD) was diagnosed according to medical history, work exposure, physical examination, and patch test findings. 36% of patients seen were diagnosed as having OHD. Electronics, hairdressing, medical, chemical, and construction were the most important industries causing OHD. In the 164 patients with OHD, 58.5% had irritant contact dermatitis (ICD) and 41.5% allergic contact dermatitis (ACD). Dorsal fingers, nail folds, and dorsal hands were most frequently involved in patients with ACD; dorsal fingers, volar fingers and fingertips were most frequently involved in those with ICD. Using logistic regression analysis, we were able to identify the most important clinical presentations that predicted the types of OHD, ACD versus ICD. Patients with atopic history and palm involvement were more likely to have ICD, and those with nail fold involvement more likely to have ACD. In patients with ACD, the most important allergens were dichromate, nickel, cobalt, fragrance mix, epoxy resin, thiuram mix, and p-phenylenediamine. In this study, we identified the important industries and causal agents for OHD. Future preventive measures focused on these industries and agents to reduce OHD will be warranted.

Cutaneous reactions to surgical preparations and dressings

A prospective study of 100 surgical patients was undertaken to identify causes of contact dermatitis. Patch testing with the North American Contact Dermatitis Standard Series and additional agents used in the surgical preparation and dressing was performed in 11 patients with post-operative dermatitis or a history of tape allergy. 12 patients were diagnosed as having irritant (mechanical) contact dermatitis. One patient had allergic contact dermatitis to benzoin postoperatively; another patient with a history of an adhesive tape reaction had a positive patch test to thiuram mix, rubber accelerators formerly present in adhesive tapes. Our findings indicate that irritant contact dermatitis is a common problem in the surgical patient. Allergic contact dermatitis is less common, occurring in 2 of the 100 patients.

Effects of the pesticide thiuram: genome-wide screening of indicator genes by yeast DNA microarray

Although there have been studies on the toxicity of the pesticide thiuram, the present study is the first one to attempt to integrate a whole genomic response using microarray technology. From the DNA microarray experiment it was found that exposure to thiuram led to alterations of gene expression in yeast cells and that many genes involved in detoxification and stress response were highly induced. The induced genes were classified according to the MIPS yeast database. The induction of genes concerned with folding and proteolysis reflects the protein denaturing and degradation effects of the thiuram treatment The induction of genes involved in redox and defense against reaction oxygen species also suggests that thiuram has other effects, such as oxidative stress. Genes classified for carbohydrate metabolism and energy were also highly induced, and these gene products may play the role of providing the energy for the detoxification mechanism. In addition, in view of the induction of some genes involved in DNA repair, thiuram potentially causes DNA damage. Therefore, as stated in previous reports, thiuram is a potential positive toxic chemical. On the other hand, YKL071W, YCR102C, YLR303W, and YLL057C were selected based on the result of a DNA microarray experiment and used for the promoter activity assay. Thiuram treatment affected the promoter of these genes, indicating that this technique could be used for the selection of biomarker candidates.

Allergic contact dermatitis from 3-iodo-2-propynyl-butylcarbamate (IPBC) - an update

Results from 3 1/2 years of routine patch testing with 3-iodo-2-propynyl-butylcarbamate (IPBC) are presented. From 1996 to 1999, a total of 3168 persons (2093 women and 1075 men) were patch tested with IPBC, and 7 cases were found to be positive. In 2 cases, sensitization could be attributed to cosmetics, and in a further 2 cases cosmetics were the most likely cause of sensitisation. It is concluded that the use of IPBC in cosmetic products can lead to contact sensitization and allergic contact dermatitis. 2 of the 7 reported cases with IPBC allergy were also found positive to thiuram, and possible cross-reactivity between IPBC and thiuram is discussed.

Application of the chicken embryo in testing for embryotoxicity: thiurams

A test protocol was developed for the testing of chemicals for toxicity on the chicken embryo. The protocol called for a continuous monitoring of the developing embryo for those that died before maceration. The eggs were injected on day 3, and the test was continued up to day 14 of incubation. The following parameters of embryotoxicity were used: early deaths (spanning the first 2 d after injection), late deaths with malformed embryos, late deaths with nonmalformed embryos, and malformed survivors. The order of embryotoxic potency, in descending order, among the thiurams was tetramethylthiuramdisulfide, tetramethylthiurammonosulfide, tetraethylthiuramdisulfide. It was found that late deaths were seen in 70% of the cases with malformations. The most common types of malformations were eye defects and open coeloms. Dead embryos frequently had multiple malformations. In lethal cases, embryonic development terminated at stages 25/26 and 29 on the Hamburger-Hamilton scale.

Neurotoxicity and behavioral effects of thiram in rats

Eight of 24 female rats fed 66.9 mg/kg-day of thiram developed neurotoxicity. The neurotoxic effects were characterized by ataxia and paralysis of the hind legs. There were demyelination, degeneration of the axis cylinders, and presence of macrophages in the nerve bundle of the sciatic nerve. Degeneration in the ventral horn of the lower lumbar region of the spinal cord was evidenced by chromatolysis of motorneurons, pyknosis, and satellitosis. During a second experiment, 4 of 24 females fed 65.8 mg/kg--day also developed ataxia and paralysis. An additional 9 females showed clasping of the hind feet when picked up by the tail. Nerve conduction could not be measured for one severely ataxic rat and the electromyogram indicated a loss of motor unit function. Histopathology of this rat, along with the others, suggests the peripheral nerve as the primary site of the lesion. Thiram also caused behavioral changes in apparently normal rats. The walking pattern of the hind legs was altered with decreases in stride width and the angle between contralateral steps. These rats required significantly more shock-motivations and cleared a lower height in a jump/climb ability test. An open-field study indicated that thiram caused hyperactivity in the nonataxic rats of both sexes. Three of 24 rats fed 95.8 mg/kg-day of ferbam also developed ataxia or paralysis.

Chemical changes in rubber allergens during vulcanization

Allergic contact dermatitis to rubber is caused by residues of chemicals used in manufacturing a rubber product. Several different additives are used to achieve a final product of the desired characteristics. Accelerators such as thiurams, dithiocarbamates, and mercaptobenzothiazoles are often among the additives responsible for allergic reactions recognized by dermatologists. The chemistry of the vulcanization process is complicated; as it occurs at an elevated temperature with a mixture of reactive chemicals, the compositions of the initial and final products differ. This paper investigates the changes in composition of common allergens during vulcanization, doing so by chemically analysing various rubber formulations at different stages of the process. Major changes were found in which added chemicals were consumed and new ones produced. An important observation is that thiuram disulfides rarely appear in the final rubber although they may have been used as additives. Instead, thiurams are often converted to dithiocarbamates or to products formed by addition to mercaptobenzothiazole structures, if these have been used together with thiurams as accelerators.

Contact allergy and exposure patterns to thiurams and carbamates in consecutive patients

Sensitization to rubber is most often due to sensitization to thiurams. Positive patch test reactions to carbamates are less frequent, and usually only diagnosed in patients with positive patch test reactions to thiurams as well. The aim of the present study was to describe the relative frequency of sensitization to thiuram mix (TH mix) and zinc diethyldithiocarbamate (ZDC) in a population where the exposure to these chemicals from rubber gloves was previously studied and considered to be of approximately the same order of magnitude. The thiuram derivatives seemed to be the most important sensitized (frequency 2.8%) compared to ZDC (frequency 0.5%), which has been the most frequently reported sensitizer among the carbamates in rubber gloves. An interesting observation was that the probability that the patient was reacting to ZDC was strongly associated with the strength of the patch test reaction to TH mix. This observation may add a new aspect to the discussion about cross-reactivity versus concomitant sensitization of thiurams and carbamates.

Contact sensitivity to chromate: comparison at a London contact dermatitis clinic over a 10-year period

It has been argued that for chromate sensitivity to be reduced, then ferrous sulfate should be added to cement. This has not yet been done in the UK. To explore this further, we have looked at the comparative sensitization rates of patients attending the St. John's Institute of Dermatology Contact Dermatitis Clinic between the years 1982-3 and 1992-3. Patch-test-positive rates for females were not significantly different between the 2 populations studied (1982-3, 1.59% and 1992-3, 1.99% p NS). Similarly, there was no significantly different rate between the males (1982-3, 3.99% and 1992-3, 4.25% p NS) in the same time period. There was no difference in the distribution of eczema in chromate-positive subjects, nor of cobalt co-sensitization, a crude indicator of sensitization via cement. This work demonstrates no appreciable difference in the frequency of chromate sensitivity between the early 1980s and 1990s in London. Adding ferrous sulfate to cement may help to lower the frequency in the future.

Contact Allergy in Danish Healthcare Workers: A Retrospective Matched Case-control Study

Contact dermatitis in healthcare workers is a world wide problem. We conducted a retrospective observational study of the patch-test results of 1402 healthcare workers and 1402 matched controls with contact dermatitis who were treated at 3 hospitals departments in Denmark between 2007 and 2014. The primary objective was to determine whether healthcare work was associated with contact allergy to thiuram mix. Unadjusted univariate analyses revealed that healthcare work was significantly associated with occupational contact dermatitis and hand dermatitis. Contact allergy to thiuram mix was more common in healthcare workers was significantly associated with having occupational contact dermatitis, hand dermatitis and older age. In conclusion, we report here a potential problem of contact allergy to thiurams in healthcare workers with contact dermatitis. Legislative authorities may in the future focus on the use of rubber accelerators in, for example, protective gloves, which are widely used by healthcare professionals.

The problem of the sensitization to dithiocarbamates in thiuram-allergic patients

Because of the occurrence of hand dermatitis in members of a surgical staff due to allergy to thiuram-containing rubber gloves, an investigation was performed about cross-sensitization between thiuram compounds and dithiocarbamates. Positive reactions to dithiocarbamates were compared with reactions to 8 brands of hypo-allergenic or dithiocarbamate-containing surgical gloves. There appeared to be a marked difference in reactions to the dithiocarbamate-containing gloves. Some brands gave negative or nearly always negative reactions, while other brands caused many positive reactions. Thiuram-allergic patients were advised to wear nonreacting rubber gloves or PVC gloves.

Decreasing allergic contact dermatitis frequency through dermatotoxicologic and epidemiologic based intervention?

Allergic contact dermatitis (ACD) affects millions of people worldwide. In an attempt to decrease the incidence of contact dermatitis, several countries have implemented legislations to reduce the population's exposure to known sensitizers. To determine whether these legislations have been effective, we reviewed several studies examining trends in patch test reactivity before and after implementation of these legislations. Common sensitizers studied include nickel, gluceryl monothioglycolate fragrances, chromate, and thiuram. Overall, the evidence suggests a decreasing trend of ACD with appropriate formulation changes, however some of the data may be confounded by biases, and additionally, exposure to the sensitizer may still exist via non-compliance to regulations by small manufacturers. In the future population based studies should be conducted to more accurately assess trends in ACD.

Allergic contact dermatitis due to thiuram exposure from a fungicide

A 49-year-old man developed a widespread eczematous eruption following contact with plants sprayed with a fungicide. Patch testing revealed a strong reaction to thiuram mix and several of the individual thiuram mix constituents. The fungicide contained tetramethylthiuram disulphide, a thiuram chemical. Thiurams are widely recognized as a cause of rubber-glove allergy; however, they are also used extensively in fungicides.

Patch testing discordance alert: false-negative findings with rubber additives and fragrances

From July 1996 through June 1998, the North American Contact Dermatitis Group evaluated 318 patients for suspected contact dermatitis by patch testing simultaneously with Finn Chambers and the T.R.U.E. Test allergen system. Discrepancies between the two systems were found in some of the results, particularly with fragrance and rubber allergens. These results suggest that positive reactions to fragrance, thiuram, and carba mix allergens may be missed if the T.R.U.E. Test is used alone.

Lymphocyte transformation and thiuram sensitization

The use of a lymphocyte transformation test (LTT) to confirm allergic contact dermatitis from thiurams has been investigated. The responses of peripheral blood mononuclear cells (PBMC) from thiuram-sensitive and non-sensitive individuals following culture with dimethylcarbamoyl-protein (human serum albumin; HSA) and dimethylthiocarbamoyl-HSA conjugates has been compared. Only PBMC from those patients who were patch-test-positive with thiuram-mix and sensitized to tetramethylthiuram monosulphide (TMTM) or TMTM and tetramethylthiuram disulphide (TMTD) exhibited significant proliferative responses to these conjugates. Thiuram-patch-test-negative patients and control donors with no history of allergic contact dermatitis failed to mount a significant response to any concentration of either conjugate. Two of the thiuram-sensitive patients were also nickel-patch-test-positive, and PBMC isolated from these donors, but not from nickel-patch-test-negative patients, proved positive in a nickel LTT. The data reveal that relevant hapten-protein conjugates are capable of provoking specific human lymphocyte proliferative responses in vitro, and that, using this technique, the LTT can, in principle, be used for the investigation and/or diagnosis of skin sensitization to lipophilic contact allergens.

Effect of antibiotics on in vitro and in vivo avian cartilage degradation

Antibiotics are used in the livestock industry not only to treat disease but also to promote growth and increase feed efficiency in less than ideal sanitary conditions. However, certain antibiotic families utilized in the poultry industry have recently been found to adversely affect bone formation and cartilage metabolism in dogs, rats, and humans. Therefore, the first objective of this study was to determine if certain antibiotics used in the poultry industry would inhibit in vitro cartilage degradation. The second objective was to determine if the antibiotics found to inhibit in vitro cartilage degradation also induced tibial dyschondroplasia in growing broilers. Ten antibiotics were studied by an avian explant culture system that is designed to completely degrade tibiae over 16 days. Lincomycin, tylosin tartrate, gentamicin, erythromycin, and neomycin sulfate did not inhibit degradation at any concentration tested. Doxycycline (200 microg/ml), oxytetracycline (200 microg/ml), enrofloxacin (200 and 400 microg/ml), ceftiofur (400 microg/ml), and salinomycin (10 microg/ml) prevented complete cartilage degradation for up to 30 days in culture. Thus, some of the antibiotics did inhibit cartilage degradation in developing bone. Day-old chicks were then administered the five antibiotics at 25%, 100%, or 400% above their recommended dose levels and raised until 21 days of age. Thiram, a fungicide known to induce experimental tibial dyschondroplasia (TD), was given at 20 ppm. Birds were then killed by cervical dislocation, and each proximal tibiotarsus was visually examined for TD lesions. The results showed that none of these antibiotics significantly induced TD in growing boilers at any concentration tested, whereas birds given 20 ppm thiram had a 92% incidence rate.