Contact allergy trends in Sweden - a retrospective comparison of patch test data from 1992, 2000, and 2009

Colophonium-related Allergic Contact Dermatitis Caused by Medical Adhesive Tape Used to Prevent Skin Lesions in Soldiers

Medical adhesive tapes are commonly recommended for the prevention of friction blisters during hiking and military marches. The aim of this paper is to report on the results of investigations into an outbreak of tape-related foot dermatitis in 26 military conscripts following continuous use of medical adhesive tapes for several days during a field exercise. Patch tests were performed using baseline series and aimed testing was performed with colophonium-related substances and different medical adhesive tapes. Contact allergy to the adhesive tapes used was found in 20 (77%) subjects, and contact allergy to colophonium in 16 (61%). Chemical analysis detected colophonium-related substances in the culprit tapes. Compared with consecutive dermatitis patients investigated at our Department of Occupational and Environmental Dermatology in the previous 10 years, conscripts with colophonium allergy had increased odds ratios for concomitant contact allergy to phenol formaldehyde resins and fragrance substances including hydroperoxides of limonene and linalool. The results show that prolonged use of medical adhesive tapes on intact skin carries a high risk for allergic contact dermatitis. Prior to their introduction on the market, medical devices should be assessed for possible side-effects.

The sesquiterpene lactone mix: A review of past, present and future aspects

The sesquiterpene lactones (SLs) are secondary plant metabolites, which are widespread in the Compositae/Asteraceae plant family. The first SLs were detected more than 100 years ago, and allergic contact dermatitis from Compositae has been reported since the beginning of the 1900s, but it was not until the late 1960s and early 1970s that a collaboration between dermatologists, chemists and botanists led to the detection of SLs as the main allergens of Compositae plants. In the 1980s, the SL mix, consisting of equimolar amounts of alantolactone, costunolide and dehydrocostus lactone, was developed as a screening agent for Compositae sensitisation. Today, after inclusion of SL mix in the baseline series, the mean prevalence of reactions in Europe is around 1%, and in North America 0.8%. In countries outside Europe and North America, the prevalence ranges between 0% and 10.7%. The detection rate of SL mix is lower than that of some plant extracts, and ideally, SL mix should be supplemented with a mix of SLs from locally prevalent allergenic plants. The prevalence of positive reactions to SL mix suggests continued baseline testing in most European countries, North America, New Zealand, Australia and probably some Chinese centres.

Artificial Intelligence That Predicts Sensitizing Potential of Cosmetic Ingredients with Accuracy Comparable to Animal and In Vitro Tests-How Does the Infotechnomics Compare to Other "Omics" in the Cosmetics Safety Assessment?

The aim of the current study was to develop an in silico model to predict the sensitizing potential of cosmetic ingredients based on their physicochemical characteristics and to compare the predictions with historical animal data and results from "omics"-based in vitro studies. An in silico model was developed with the use of WEKA machine learning software fed with physicochemical and structural descriptors of haptens and trained with data from published epidemiological studies compiled into estimated odds ratio (eOR) and estimated attributable risk (eAR) indices. The outcome classification was compared to the results of animal studies and in vitro tests. Of all the models tested, the best results were obtained for the Naive Bayes classifier trained with 24 physicochemical descriptors and eAR, which yielded an accuracy of 86%, sensitivity of 80%, and specificity of 90%. This model was subsequently used to predict the sensitizing potential of 15 emerging and less-studied haptens, of which 7 were classified as sensitizers: cyclamen aldehyde, N,N-dimethylacrylamide, dimethylthiocarbamyl benzothiazole sulphide, geraniol hydroperoxide, isobornyl acrylate, neral, and prenyl caffeate. The best-performing model (NaiveBayes eAR, 24 parameters), along with an alternative model based on eOR (Random Comittee eOR, 17 parameters), are available for further tests by interested readers. In conclusion, the proposed infotechnomics approach allows for a prediction of the sensitizing potential of cosmetic ingredients (and possibly also other haptens) with accuracy comparable to historical animal tests and in vitro tests used nowadays. In silico models consume little resources, are free of ethical concerns, and can provide results for multiple chemicals almost instantly; therefore, the proposed approach seems useful in the safety assessment of cosmetics.

Cobalt nanoparticles cause allergic contact dermatitis in humans

BACKGROUND

Cobalt (Co) causes allergic contact dermatitis (ACD) and the emerging use of Co nanoparticles (CoNPs) warrants gaining further insight into its potential to elicit ACD in sensitized individuals.

OBJECTIVES

The aims of the study were to clarify to what extent CoNPs may elicit ACD responses in participants with Co contact allergy, and to evaluate whether the nanoparticles cause a distinct immune response compared with cobalt chloride (CoCl2) in the skin reactions.

METHODS

Fourteen individuals with Co contact allergy were exposed to CoNPs, CoCl2, a Co-containing hard-metal disc (positive control), and an empty test chamber (negative control) by patch testing. Allergic responses were evaluated clinically by a dermatologist at Days 2, 4 and 7. At Day 2, patch-test chambers were removed, and remaining test-substance and skin-wipe samples were collected for inductive-coupled plasma mass spectrometry (ICP-MS) analysis. Additionally, skin biopsies were taken from patch-test reactions at Day 4 for quantitative real-time polymerase chain reaction analysis, histopathology and ICP-MS analysis of Co skin penetration.

RESULTS

Patch testing with CoNPs elicited allergic reactions in Co-sensitized individuals. At all timepoints, clinical assessment revealed significantly lower frequencies of positive patch-test reactions to CoNPs compared with CoCl2 or to the positive control. CoNPs elicited comparable immune responses to CoCl2. Chemical analysis of Co residues in patch-test filters, and on skin, shows lower doses for CoNPs compared with CoCl2.

CONCLUSIONS

CoNPs potently elicit immune responses in Co-sensitized individuals. Even though patch testing with CoNPs resulted in a lower skin dose than CoCl2, identical immunological profiles were present. Further research is needed to identify the potential harm of CoNPs to human health.

Systematic review on skin adverse effects of important hazardous hair cosmetic ingredients with a focus on hairdressers

BACKGROUND

The burden of occupational hand eczema in hairdressers is high, and (partly strong) allergens abound in the hair cosmetic products they use.

OBJECTIVES

To systematically review published evidence concerning contact allergy to an indicative list of active ingredients of hair cosmetics, namely, p-phenylenediamine (PPD), toluene-2,5-diamine (PTD), persulfates, mostly ammonium persulfate (APS), glyceryl thioglycolate (GMTG), and ammonium thioglycolate (ATG), concerning the prevalence of sensitization, particularly in terms of a comparison (relative risk; RR) between hairdressers and non-hairdressers.

METHODS

Following a PROSPERO-registered and published protocol, eligible literature published from 2000 to February 2021 was identified, yielding 322 publications, and extracted in standardized publication record forms, also considering risk of bias.

RESULTS

Based on 141 publications, the contact allergy prevalence to PPD was 4.3% (95% CI: 3.8-4.9%) in consecutively patch tested patients. Other ingredients were mostly tested in an aimed fashion, yielding variable, and partly high contact allergy prevalences. Where possible, the RR was calculated, yielding an average increased sensitization risk in hairdressers of between 5.4 (PPD) and 3.4 (ATG). Additional evidence related to immediate-type hypersensitivity, experimental results, exposures, and information from case reports was qualitatively synthesized.

CONCLUSIONS

An excess risk of contact allergy is clearly evident from the pooled published evidence from the last 20 years. This should prompt an improvement in working conditions and product safety.

Contact allergy to haptens in the Swedish baseline series: Results from the Swedish Patch Test Register (2010 to 2017)

BACKGROUND

Allergic contact dermatitis has considerable public health impact and causative haptens vary over time.

OBJECTIVES

To report the prevalence of contact allergy to allergens in the Swedish baseline series 2010 to 2017, as registered in the Swedish Patch Test Register.

METHODS

Results and demographic information for patients tested with the Swedish baseline series in 2010 to 2017 were analysed.

RESULTS

Data for 21 663 individuals (females 69%) were included. Females had significantly more positive patch tests (54% vs 40%). The reaction prevalence rates were highest for nickel sulfate (20.7%), fragrance mix I (7.1%), Myroxylon pereirae (6.9%), potassium dichromate (6.9%), cobalt chloride (6.8%), methylchloroisothiazolinone/methylisothiazolinone (MCI/MI; 6.4%), MI (3.7%), colophonium (3.5%), fragrance mix II (3.2%), and formaldehyde (3.2%). Myroxylon pereirae reaction prevalence increased from 5% in 2010 to 9% in 2017 and that for methyldibromo glutaronitrile from 3.1% to 4.6%. MCI/MI and MI reactions decreased in prevalence after 2014. Nickel reaction prevalence decreased among females aged 10 to 19 years.

CONCLUSIONS

Nickel remains the most common sensitizing agent, with reaction prevalence decreasing among females younger than 20 years. The changes in MCI/MI and MI reaction prevalence mirrored those in Europe. The register can reveal changes in contact allergy prevalence over time among patients patch tested in Sweden.

Dermal exposure to cobalt studied in vitro in keratinocytes - effects of cobalt exposure on inflammasome activated cytokines, and mRNA response

BACKGROUND

Cobalt is a dermal sensitizer, and keratinocytes respond to cobalt exposure by releasing proinflammatory mediators, regulating the immune response.

OBJECTIVE

To determine the effect of cobalt on the inflammasome associated cytokine- and gene expression in cultured human keratinocytes (HaCaT). Cultivation in low- or high calcium conditions model separate differentiation states of keratinocytes in the skin.

METHOD

HaCaT cells in two different states of differentiation were exposed to cobalt chloride and caspase-1 activity as well as the production of IL-1β, IL-18 and gene expression of IL1B, IL18, NLRP3, CASP1, and PYCARD was quantified.

RESULTS

High cobalt chloride exposure mediated significant increase in caspase-1 activity, cytokine levels, and IL1B and NLRP3 expression with a corresponding regulatory decrease for CASP1 and PYCARD expression. No difference between high- and low calcium culturing conditions modelling differentiation states was detected.

CONCLUSIONS

Our data suggest that HaCaT cells respond with inflammmasome associated activity upon cobalt exposure in a concentration-dependent manner. These mechanisms could be of importance for the understanding of the pathophysiology behind allergic sensitization to dermal cobalt exposure.

Dose- and time-dependent changes in viability and IL-6, CXCL8 and CCL2 production by HaCaT-cells exposed to cobalt. Effects of high and low calcium growth conditions

Background

Sensitization requires exposure to an allergen with subsequent production of a “danger “signal. In the skin, keratinocytes are the main producers of these signals.

Objective

To compare dose- and time-effects of cobalt on the viability of and cytokine release from HaCaT cells cultured at low or high calcium.

Method

To model two separate states of differentiation of keratinocytes, HaCaT cells were cultured under low or high calcium conditions. HaCaT were exposed to different concentrations of cobalt chloride (10 μm to 5 mM) over time (30 minutes– 48 hours). Cell viability was measured with the Cell-Titer Blue Viability assay. Cytokine production was measured using a bead-based immunoassay and flow cytometry. Gene expression was quantified using qPCR. Data was analyzed by ANOVA and linear mixed model.

Results

Viability of the cells was dose- and time-dependent. A linear mixed statistical model showed that cobalt exposure induces increase in IL-6, CXCL8 and CCL2 production over time and whereas increase of IL-6 and a decrease of CCL2 was associated with increasing cobalt chloride concentrations. When comparing the cells incubated under high and low calcium conditions, the more differentiated cells in the high concentration were found to exert a stronger response in terms of IL-6 release.

Conclusions

Our data suggest that cobalt chloride triggered an alarm system in HaCaT cells, and proinflammatory cytokines/chemokines were secreted in a dose- and time-dependent manner. When high and low calcium incubations were compared, the difference was seen only for IL-6. These findings indicate that the effect of cobalt chloride on cell toxicity occurs throughout the living epidermis.

Patch Test Results to European Baseline Series in Turkey: A Prospective and Multicenter Study

BACKGROUND

Patch testing with the European Baseline Series (EBS) is an essential diagnostic tool for the assessment of allergic contact dermatitis.

OBJECTIVE

The aims of the study were to describe the most common contact allergens identified with patch testing in Turkey and to establish the distribution of contact allergens among different regions in Turkey.

PATIENTS AND METHODS

Twelve centers consisting of tertiary health care institutions were included in the study. A total of 1169 patients were patch tested with the EBS from 2015 to 2017.

RESULTS

A total of 596 patients (51.0%) had 1 or more positive patch test reactions to the EBS. A total of 30.2% (n = 353) of those tested had clinical relevance. Contact sensitivity was more common in young patients. The most common 10 allergens were nickel sulfate (20.4%), followed by textile dye mix (8.6%), cobalt chloride (8.3%), potassium dichromate (8.0%), p-phenylenediamine base (4.5%), balsam of Peru (4.3%), methylchloroisothiazolinone/methylisothiazolinone (3.8%), thiuram mix (3.6%), fragrance mix I (3.0%), and methylisothiazolinone (2.9%).

CONCLUSIONS

This study provides a comprehensive profile of patch test results with the EBS in Turkey. An ongoing decrease in contact allergy to methylchloroisothiazolinone/methylisothiazolinone and methylisothiazolinone was observed. Textile dye mix and p-phenylenediamine are beginning to pose a new risk in Turkey.

Chromium and leather: a review on the chemistry of relevance for allergic contact dermatitis to chromium

Abstract

As other causes decline in importance, chromium-tanned leather has become a more important source for chromium allergy, which affects around 1% of the general population. The aim of this review is to give suggestions on how to minimize the risk of leather-related allergic contact dermatitis, which can be elicited in chromium-allergic persons by hexavalent and trivalent chromium released from leather. Hexavalent chromium is the more potent chromium form and requires a lower skin dose to elicit allergic reactions. It is formed on the surface of some, antioxidant-free, leathers at dry conditions (< 35% relative humidity) and is influenced by the tanning process and other conditions, such as UV irradiation, contact with alkaline solutions, and leather age. Trivalent chromium is the dominant form released from chromium-tanned leather and its released amount is sufficient to elicit allergic reactions in some chromium-allergic individuals when they are exposed repetitively and over longer time (days – months). A low initial test result (< 3 mg/kg) for hexavalent chromium with the current standard test (ISO 17075) does not guarantee a low release of chromium from the leather or a low release of hexavalent chromium under typical exposure conditions during the service life of the leather. Information, labels, and certificates regarding leather products are often insufficient to protect chromium-allergic individuals. Correct labelling and information on the possible content of different allergens, as well as different tanning alternatives for certain leather products, are crucial.

Graphical abstract

Comparison of Nickel Sulfate 2.5% and Nickel Sulfate 5% for Detecting Nickel Contact Allergy

BACKGROUND

Nickel is among the most common contact allergens found on patch testing worldwide and, because of its ubiquitous nature in our environment, often has important implications for allergen avoidance strategies. In both North America and Europe, nickel positivity is found in approximately 20% of patients who undergo patch testing. Whereas in North America, nickel sulfate is typically tested at a concentration of 2.5%, in Europe, it is tested at a 5% concentration.

OBJECTIVE

The primary objective was to assess the differences in patch test positivity to nickel sulfate 2.5% and 5%.

METHODS

We investigated 205 consecutive patients between September 2017 and February 2018 who were tested to nickel sulfate at concentrations of both 2.5% and 5%.

RESULTS

Among the 205 patients tested, 33% were positive (+, ++, or +++) to at least 1 concentration of nickel sulfate, 20% were positive to nickel sulfate 2.5%, and 31% were positive to nickel sulfate 5% (χ1(N = 205) = 16.1, P = 0.0001). Patients were 6.5 times more likely to have a positive reaction to nickel sulfate 5% than 2.5% (odds ratio 95% confidence interval, 2.3-25.6).

CONCLUSIONS

Given our findings, we propose an additional evaluation of nickel sulfate 5% as a standard allergen for patch testing in North America.

Using Patch Testing to Improve Therapeutic Outcome in the Treatment of Hand Eczema in Vietnamese Patients

BACKGROUND:

Hand eczema is a common chronic and relapsing skin disease with various clinical features. Hand eczema aetiology can be allergic contact dermatitis (ACD), irritant contact dermatitis (ICD), atopic dermatitis (AD) and unknown or combination causes. If the causative agents are not detected treatment of hand eczema will be a failure. A patch test can be useful to detect causative agents in suspected allergic contact hand eczema. Then patients will avoid contacting them. This results in the improvement of hand eczema. In Vietnam, patch test has not been used before, so we conduct this study.

AIM:

To identify causative allergens by using patch test with 28 standard allergens in consecutive patients.

METHODS:

A group of 300 HE patients from the National Hospital of Dermatology and Venereology (NHDV) in Vietnam were enrolled in this study. They were divided into 4 groups-ACD, ICD, AD and unknown aetiology. The patient was patch tested with 28 standard allergens to identify the causative agents.

RESULTS:

Among the 300 HE enrolled patients, ACD accounted for 72.7%, AD and ICD had the same rate of 12.7%. 39.3% of the patients had a positive patch test. Reaction to nickel sulfate was the most common (10.3%), followed by potassium dichromate (9.7%), cobalt (4%) and fragrance mix (3.1%). About one-third of the cases had relevant clinical reactions correlated with the contact agents and clinical history. Males reacted to cement, thiuram mix and formaldehyde more than females, while females reacted to a nickel more than males.

CONCLUSIONS:

Hand eczema has variable clinical features and diverse aetiology. ACD is an important cause of hand eczema that can be managed with a patch test to detect causative allergens. Nearly 40% of HE cases had positive patch test. Relevant patch test reactions were seen in one-third of the patients. We propose using patch test detect causative agents in suspected allergic contact hand eczema. Then patients will avoid contacting them. This results in the improvement of hand eczema.

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.

Sensitization to, and allergic contact dermatitis caused by, colophonium in north-eastern Italy in 1996 to 2016 with a focus on occupational exposures

BACKGROUND

Colophonium is a natural substance derived from Pineaceae trees. It is used in a wide range of consumer and occupational products because of its tackiness, and is a known sensitizer.

OBJECTIVES

To analyse the temporal trend of contact allergy to colophonium in north-eastern Italy, and to evaluate the associations with occupations in our geographical area.

METHODOLOGY

From 1996 to 2016, 27 381 patients with suspected allergic contact dermatitis were patch tested in north-eastern Italy. Individual characteristics were documented by use of a standardized questionnaire in 6 departments of dermatology or occupational medicine.

RESULTS

The overall prevalence of colophonium sensitization was 1.67%; the prevalence was significantly higher in women (1.75%) than in men (1.49%). No significant differences among departments were observed. We found significant associations between colophonium sensitization and being a student (odds ratio [OR] 4.64; 95% confidence interval [CI]: 1.04-20.6), being a farmer or fishermen (OR 3.63; 95%CI: 1.21-10.84), being a housekeeper (OR 2.02; 95%CI: 1.08-3.77), and being retired (OR 2.06; 95%CI: 1.08-3.92).

CONCLUSION

Our study showed that contact allergy to colophonium is still relevant in north-eastern Italy. The frequency of sensitization has dropped significantly over a period of 10 years, but students and farmers/fishermen still have sensitization prevalences above 3.5%. Our results are in line with European data.

Screening for skin-sensitizing allergens among patients with clinically suspected allergic contact dermatitis

Objectives:

To detect common skin-sensitizing agents among patients experiencing allergic contact dermatitis (ACD).

Methods:

This was a retrospective study of 152 patients with clinically suspected ACD who underwent patch testing in an allergy clinic at King Khalid University Hospital, Riyadh, Kingdom of Saudi Arabia between January 2012 and February 2015. Of these patients, only 74 (48%) patients reacted to one or more contact allergens. This group of patients included 58 (78.4%) women and 16 (21.6%) men (mean age: 37.8±13.8 years). Patch testing was performed using the thin-layer rapid-use epicutaneous patch test panels.

Results:

Nickel sulfate was the most common sensitizing agent, with 26 (35.1%) patients yielding a positive result; followed by p-phenylenediamine in 17 (22.9%), butyl-tetra-phenol formaldehyde in 12 (16.2%), gold sodium thiosulfate in 10 (13.5%), and thimerosal in 6 (8.1%) patients. Nickel reactivity was significantly higher among women (41.4%) than among men (12.5%) (p<0.0001). Similarly, gold reactivity among women (15.5%) was also higher than among men (6.2%) (p≤0.02).

Conclusion:

The high level of skin sensitization due to nickel, PPD, and gold in patients with ACD emphasizes the need for measures to decrease exposure to these sensitizing agents.

The role of nickel allergy in hand dermatitis and its impact on handling cupronickel currency coins. A comparative cohort study from Kuwait

INTRODUCTION

Contact with nickel-releasing coins as a cause of hand dermatitis has been debated.

AIM

Studying a hand dermatitis risk from handling Kuwaiti cupronickel coins among nickel-allergic and nickel non-allergic subjects.

MATERIAL AND METHODS

One hundred hand dermatitis patients (group I: nickel-allergic) and 100 matched patients (group II: nickel non-allergic) were selected from over 500 hand dermatitis cases seen between September 2014 and September 2015. Nickel released from Kuwaiti cupronickel coins immersed in a standardized artificial sweat solution was measured at 1, 24, 48, 144 and 168 h at room temperature. Subjects in both groups were exposed to nickel releasing coins. The process was repeated after 3 months using nickel coated coins as controls.

RESULTS

Nickel released from 20, 50 and 100 fils Kuwaiti cupronickel coins at 1 week was 28.64, 32.76, 35.76 μg/cm²/week, respectively. Ninety-one patients (29 males, 62 females) in group I and 87 patients (38 males, 49 females) in group II completed the study. 47.3% in group I vs. 13.8% in group II developed dermatitis on exposure to nickel releasing coins. Nickel coated coins resulted in dermatitis in 8.8% of group I vs. 5.7% in group II.

CONCLUSIONS

Nickel is released significantly from cupronickel Kuwaiti coins. Handling of coins caused dermatitis more often in patients with nickel-allergy compared to nickel non-allergic patients.

Pediatric patch testing: A 10-year retrospective study

BACKGROUND

Patch testing is the gold standard for diagnosing allergic contact dermatitis in children.

OBJECTIVE

To present a 10-year retrospective review of pediatric patch testing at our institution.

METHODS

Data from patients 18 years or younger who presented for patch testing from February 1, 2005, to May 31, 2015, were entered into a database. Patch testing was performed according to North American Contact Dermatitis Group standards. A positive reaction was defined as any allergen for which the patient had a 1+ or greater reaction and provided avoidance information.

RESULTS

A total of 157 patients with a mean (SD) age of 12.3 (4.1) years were evaluated. The 2 most frequent allergens were nickel and cobalt. Most patients were referred by dermatologists for suspected allergic contact dermatitis (72.3%). Dermatitis was present for more than 2 years in most cases (n = 67 [46.2%]), from 6 months to 2 years (n = 49 [33.8%]), and for less than 6 months (n = 29 [20.0%]). Males were more likely to have a positive reaction to fragrance mix 1 compared with females (P = .02). No significant association was found between age and allergen sensitivity. Those with a history of atopy were more likely to have a positive reaction to cobalt (P = .008) and chromium (P = .03). Sixty patients (38.2%) returned for follow-up, and 37 (60.7%) reported improvement; most (n = 54 [88.5%]) were being treated with topical corticosteroids.

CONCLUSION

Our study of pediatric patch testing can provide information regarding common allergens in children, which can enhance patient care. Primary care practitioners may benefit from awareness of patch testing as an alternative to prescribing systemic immunosuppressants.

High prevalence of contact allergy in adolescence: results from the population-based BAMSE birth cohort

BACKGROUND

Contact allergy is common among adults. However, little is known about the prevalence in adolescents.

OBJECTIVES

To assess the prevalence of allergy to common contact allergens in Swedish adolescents in the general population.

PARTICIPANTS AND METHODS

The BAMSE cohort is a population-based birth cohort with the main aim of studying the risk factors for asthma, rhinitis, and atopic dermatitis. Patch testing was performed at the 16-year follow-up. The test (TRUE Test(®) ) was applied at home, and removed 2 days later by nurses, who recorded and photographed the results. Dermatologists made final assessments on the basis of photographs and protocols.

RESULTS

Two thousand two hundred and eighty-five participants (88% of all 16-year follow-up participants) were patch tested; 15.3% had at least one positive reaction. Contact allergy was more common in girls than in boys (17.0% versus 13.4%, p = 0.018). Sensitization to nickel was most common (7.5%), followed by sensitization to fragrance mix I (2.1%) and p-tert-butylphenol formaldehyde resin (1.9%). Nickel allergy was more frequent in girls (9.8% versus 4.9%, p < 0.001). Solitary sensitization to cobalt was more common than co-sensitization to nickel and cobalt.

CONCLUSIONS

The prevalence of contact allergy in adolescents is of almost the same high magnitude as in adults. The applied method was feasible in the population-based setting.