Which test chambers should be used for acetone, ethanol, and water solutions when patch testing?

Surprising results of patch testing with the baseline series in patients with photocontact allergy to ketoprofen

OBJECTIVE

Photoallergic reactions due to topical ketoprofen are common. As some simultaneous contact allergies have been described in the literature, we aimed to get an overview of the pattern of reactivity towards common allergens in the baseline series in ketoprofen-photoallergic individuals.

METHODS

Using our database, we found 94 patients with photocontact allergy to ketoprofen diagnosed during 1999-2018. Approximately 12 800 patients patch tested with the baseline series during the same time frame served as controls. Data on patch testing with the baseline series of 518 individuals belonging to the general population were obtained from an earlier study, and a comparison of allergy rates was made with the ketoprofen group.

RESULTS

Contact allergy to fragrance mix I and Myroxylon pereirae was overrepresented among patients with photocontact allergy to ketoprofen (42.3% vs. 6.6% and 47.9% vs. 6.6%, p < 0.001, respectively). Significant overrepresentation was also shown for 4-tert-butylphenolformaldehyde resin (PTBP-F-R), phenol formaldehyde resin (PFR-2), black rubber mix, budesonide (all p < 0.001), and fragrance mix II (p = 0.02). The pattern was similar, but with lower significance levels for fragrance mix II and budesonide, regardless of whether or not the individuals had been photopatch tested because of a suspected photoallergic contact dermatitis from ketoprofen.

CONCLUSION

Contact allergy to fragrance mix I, Myroxylon pereirae, black rubber mix, PFR-2, PTBP-FR, and to a somewhat lower extent, to fragrance mix II and budesonide, is common in individuals photoallergic to ketoprofen. It remains to be seen whether sensitisation to ketoprofen leads to simultaneous sensitisation to a number of other, chemically non-related, substances.

Epoxy allergy, investigation of a modern industry

BACKGROUND

Five workers from an industry manufacturing various articles from carbon fibre reinforced epoxy plastics were referred to our department because of suspected occupational allergic contact dermatitis (OACD). When patch tested, four of them had positive reactions to components of epoxy resin systems (ERSs) that could explain their current skin problems. All of them had been working at the same workstation at a specially designed pressing machine, with operations including manually mixing epoxy resin with hardener. Multiple cases of OACD in the plant prompted an investigation including all workers with possible risk exposures at the plant.

OBJECTIVES

To investigate the prevalence of occupational dermatoses and contact allergies among the workers at the plant.

MATERIALS AND METHODS

Totally 25 workers underwent investigation that included a brief consultation with a standardized anamnesis and clinical examination followed by patch testing.

RESULTS

ERSs-related reactions were found in 7 of the 25 investigated workers. None of the seven had a history of previous exposure to ERSs and they are regarded as sensitized through work.

CONCLUSIONS

Twenty-eight percent of investigated workers showed reactions to ERSs. Of these the majority would have been missed if supplementary testing would not have been added to testing with the Swedish base line series.

Contact allergy to oxidized linalool and oxidized limonene: Patch testing in consecutive patients with dermatitis

BACKGROUND

Contact allergy to oxidized (ox.) linalool and ox. limonene has been reported to have a high prevalence, raising the question of inclusion into the baseline series. However, several important issues should be clarified and further investigated before inclusion can be warranted.

OBJECTIVES

To report the trends of ox. terpenes allergy in patients with dermatitis, features of the patch test reactions, and clinical characteristics of the patients.

METHODS

A retrospective analysis of 5773 patients was performed. All patients were patch tested with baseline series, individual ingredients of fragrance mix I and II, ox. linalool, and ox. limonene from 2013 to 2020.

RESULTS

The prevalence rates of contact allergy to ox. linalool and ox. limonene were 7.0% and 5.1%, respectively. Significantly increasing trends of contact allergy were observed. More than 95% of contact allergy cases were identified on Day 3/4. Patients with contact allergy to ox. linalool and ox. limonene were significantly younger than those with contact allergy to other fragrances and were predominantly female. Strong reactions were associated with older age and multiple fragrance allergies.

CONCLUSIONS

Contact allergy to ox. linalool and ox. limonene is becoming increasingly important, and findings show intriguing features. More studies concerning the clinical relevance before recommending these substances for screening are required.

Contact allergy to fragrance mix I and its components in individuals with photocontact allergy to ketoprofen

BACKGROUND

Contact allergy to fragrance mix I (FM I) is over-represented in patients photoallergic to ketoprofen. The prevalence of contact allergy to two components of FM I, cinnamal and cinnamyl alcohol, in ketoprofen-photoallergic patients is higher than in dermatitis patients.

OBJECTIVE

To explore the prevalence of contact allergy to FM I and its individual components in patients with photocontact allergy to ketoprofen, and to compare with a dermatitis and the general population.

METHODS

Data on patch and photopatch tests performed between 2009-2018 were collected. Ketoprofen-photoallergic patients were compared with dermatitis patients and published data on the general population regarding the prevalence and the distribution of contact allergy to FM I and its components.

RESULTS

A higher prevalence of contact allergy to cinnamyl alcohol compared with cinnamal (23.3% vs 10.0%), and eugenol compared with isoeugenol (23.3% vs 6.7%), was observed in ketoprofen-photoallergic patients, while the relationship was the opposite in the dermatitis group (0.7% vs 1.05%; 0.4% vs 0.9%). The overall prevalence of contact allergy to several components of FM I was significantly higher in ketoprofen-photoallergic patients.

CONCLUSIONS

Contact allergy to FM I and many of its components is over-represented in patients photoallergic to ketoprofen compared with dermatitis patients and the general population.

A comparative study between the two patch test systems Finn chambers and Finn chambers AQUA

BACKGROUND

Finn Chambers AQUA (FCA) is a development of the Finn Chambers (FC) test system in which the test chambers are mounted on a moisture-resistant adhesive patch. FCA has pre-fixed filter papers. Because the use of FCA does not require any extra taping or use of separate filter papers, a change from FC to FCA chambers may be beneficial for both patients and patch test technicians.

OBJECTIVES

To investigate whether there are any differences regarding detection of contact allergy when simultaneous patch testing is performed with FC and FCA.

MATERIALS AND METHODS

Results from 434 dermatitis patients simultaneously tested with 10 allergens in both FC and FCA were evaluated.

RESULTS

There were no significant differences regarding detection of positive reactions between the two test systems. There were significantly more doubtful reactions to methylisothiazolinone, fragrance mix I and hydroperoxides of linalool when testing with FCA. We only observed significantly more doubtful reactions in FC regarding nickel(II)sulfate. Irritant reactions to formaldehyde were also significantly more common when using FCA.

CONCLUSION

The FC and FCA had good agreement in detection of positive reactions. However, the results including doubtful and irritant reactions justify further research regarding optimization of the dose.

Patch Testing With Methylchloroisothiazolinone/Methylisothiazolinone Using a New Diagnostic Mix-A Multicenter Study From the International Contact Dermatitis Research Group

BACKGROUND

In the early 1980s, a preservative containing a mixture of methylchloroisothiazolinone (MCI) and methylisothiazolinone (MI) in a ratio of 3:1 was introduced. This mixture (mix) has been patch tested at 100 ppm (0.01%) worldwide and at 200 ppm (0.02%) in Sweden since 1986 and also in the European baseline series since 2014.

OBJECTIVE

A new aqueous mix of MCI 0.015% and MI 0.2% was compared with patch testing with the 2 aqueous baseline preparations of MCI/MI 0.02% and MI 0.2%.

METHODS

Four thousand three hundred ninety-seven patients with dermatitis in 12 International Contact Dermatitis Research Group dermatology departments from 3 continents were patch tested simultaneously with the 3 preparations.

RESULTS

The frequency of positive patch tests to the allergens varied between 0% and 26.7% in the 12 test centers. The new mixture MCI/MI 0.215% in aqua (aq) detected significantly more patients with MCI/MI allergy than both MCI/MI 0.02% aq (P < 0.001) and MI 0.2% aq (P < 0.001) alone and combined.

CONCLUSIONS

The results favor replacing the preparations MCI/MI 0.02% aq and MI 0.2% aq with the mixture MCI/MI 0.215% aq in the International Contact Dermatitis Research Group baseline series.

Changes in Chinese patch testing practices over 13 years: Updated cross-sectional survey and possible international implications

BACKGROUND

Patch testing, the standard method for diagnosing allergic contact dermatitis, has been utilized for over 30 years in China. A 2006 survey found that patch testing was widespread among Chinese dermatologists, but the practice and perceptions were unsatisfactory.

OBJECTIVE

To evaluate the current situation of patch testing practice and perception, we resurveyed Chinese dermatologists.

METHODS

A cross-sectional survey of Chinese dermatologists was conducted by electronic questionnaires at the 15th National Congress of Dermatology in November 2019.

RESULTS

There were 2199 valid questionnaires collected. About 75% of dermatologists performed patch testing; the majority (59.2%) utilized the baseline (standard) allergen series made in China; others used TRUE Test or the Chemotechnique Diagnostics series, a greater share compared with 2006. Most (92.8%) performed only one single reading, more than 2006. About two-thirds offered patient education after patch testing, but only 27% were executed by trained dermatologists. Dermatologists from regional hospitals more likely performed patch testing and had better perception of patch testing. The majority (88.1%) had received patch testing training, which however did not significantly improve dermatologists' perception.

CONCLUSIONS

There was an insignificant improvement in practice and perception of dermatologists compared with 2006. Further education and studies should be conducted. Similar surveys in other countries would be of interest.

S3 guidelines: Epicutaneous patch testing with contact allergens and drugs - Short version, Part 1

Epicutaneous patch testing is the diagnostic standard for the detection of allergic contact dermatitis. The present guidelines are aimed at residents and board-certified physicians in the fields of dermatology and allergology as well as other medical specialties involved in establishing the indication for patch testing and its execution in patients with contact dermatitis and other forms of delayed-type hypersensitivity. The target audience also includes other health care providers and insurance funds. Based on a systematic literature search and a formal consensus process (S3), the guidelines were developed by dermatologists in collaboration with pediatricians, occupational medicine physicians, nursing staff as well as patient representatives. The systematic methodological approach and appraisal of evidence upon which the recommendations are based are outlined in a separate method report that also contains evidence tables. The guidelines address general aspects of patch testing as well as medicolegal issues. The recommendations given relate to topics such as the indication for patch testing, informed patient consent, as well as the choice of test substances, test chambers and test site, duration of exposure, reading times and interpretation of test reactions. Furthermore, recommendations are provided with respect to endogenous and exogenous factors, specific patient groups (children, pregnant women, immunosuppressed individuals) as well as possible risks and adverse events associated with patch testing using contact allergens. Note: This publication is part 1 of the short version of the S3 guidelines for "Epicutaneous patch testing using contact allergens and drugs" (registry no. 013 - 018; date: March 20, 2019; valid until December 31, 2021). Part 2 of the short version will be published in the next issue. The long version of these guidelines can be accessed at www.awmf.org. The method report is available as online publication (https://www.awmf.org/leitlinien/detail/ll/013-018.html) and contains the evidence tables in its appendix.

The reactivity of the back revisited. Are there differences in reactivity in different parts of the back?

BACKGROUND

In the contact dermatitis literature, it is regularly stated that the patch test reactivity on various areas of the back differs, which might have a large impact on the reproducibility of patch testing.

OBJECTIVES

To investigate the reproducibility of patch testing on the upper back with regard to the left as opposed to the right side, and the medial as opposed to the lateral part of the upper back. The reproducibility over time and with regard to the reactivity pattern was also investigated.

METHODS

Thirty-one subjects with contact allergy to the metals gold (n = 19) or nickel (n = 12) were patch tested with serial dilutions, in triplicate applications, on different locations on the upper back. The Friedman test was used for statistical calculations.

RESULTS

No significant differences in the reactivity of the back were found. In all gold-allergic patients and 11 of 12 nickel-allergic patients, the allergy could be reproduced with regard to previous patch testing, but the degree of reactivity differed.

CONCLUSIONS

When a high level of standardization of the patch test technique with the same test system was used, there were no differences in patch test reactions and sites of application on the upper back.