Inter-rater variability in patch test readings and final interpretation using store-forward teledermatology.

BACKGROUND: Data regarding teledermatology for patch testing are limited. OBJECTIVES: Compare patch test readings and final interpretation by two in-person dermatologists (IPDs) with eight teledermatologists (TDs). METHODS: Patch tested patients had photographs taken of 70 screening series of allergens at 48 hours and second readings. Eight TDs reviewed photos and graded reactions (negative, irritant, doubtful, +, ++, +++) at 48 hours and second readings; in addition, they coded a final interpretation (allergic, indeterminant, irritant, negative) for each reaction. TDs rated overall image quality and confidence level for each patient and patch test reaction, respectively. Percentage of TD-IPD agreement based on clinical significance (success, indeterminate, and failure) was calculated. Primary outcome was agreement at the second reading. RESULTS: Data were available for 99, 101, and 66 participants at 48 hours, second reading, and final interpretation, respectively. Pooled failure (+/++/+++ vs negative) at second reading was 13.6% (range 7.9%-20.4%). Pooled failure at 48 hours and final interpretation was 5.4% (range 2.9%-6.8%) and 24.6% (range 10.2%-36.8%), respectively. Confidence in readings was statistically correlated with quality of images and disagreement. CONCLUSION: For patch testing, teledermatology has significant limitations including clinically significant pooled failure percentages of 13.6% for second readings and 24.6% for final interpretation.

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.

Patch Testing With a New Composition of the Mercapto Mix-A Multicenter Study from the International Contact Dermatitis Research Group.

BACKGROUND: Mercaptobenzothiazole compounds are associated with allergic contact dermatitis caused by rubber products. Several screening substances have been used for patch testing. OBJECTIVE: To compare the frequency of positive test reactions to a mercapto mix containing a higher concentration of 2-mercaptobenzothiazole with reactions to the combination of 2-mercaptobenzothiazole 2.0% and mercapto mix 2.0%. METHODS: There were 7103 dermatitis patients in 12 International Contact Dermatitis Research Group dermatology departments who were patch tested with 2-mercaptobenzothiazole 2.0% petrolatum (pet.), mercapto mix 2.0% pet., and mercapto mix 3.5% pet. RESULTS: Contact allergy to the 3 test preparations varied among the 12 centers: 2-mercaptobenzothiazole 2.0% pet. (0-2.4%), mercapto mix 2.0% pet. (0-4.9%), and mercapto mix 3.5% pet. (0-1.4%). 2-Mercaptobenzothiazole 2.0% and mercapto mix 2.0% detected a few more positive patients compared with mercapto mix 3.5%, but the difference was statistically insignificant (mercapto mix 2.0% pet., P = 1.0; 2-mercapto-benzothiazole 2.0% pet., P = 0.66). CONCLUSIONS: Mercapto mix 3.5% pet. is not better than 2-mercaptobenzothiazole 2.0% and mercapto mix 2.0% by a difference that is significant. By using only 1 test preparation (mercapto mix 3.5%), an additional hapten could be tested. No cases of suspected/proven patch test sensitization were registered.

¿Suelen ser relevantes las pruebas epicutáneas en el paciente con síndrome de boca urente? / Are Patch Test Results Usually Relevant in Patients With Burning Mouth Syndrome?

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Developing a cosmetic series: Results from the ESSCA network, 2009-2018.

BACKGROUND: There is considerable variability across European patch test centres as to which allergens are included in local and national cosmetics series. OBJECTIVES: To propose a standardized, evidence-based cosmetic series for Europe based on up-to-date analysis of relevant contact allergens. METHODS: We collated data from the European Surveillance System on Contact Allergies (ESSCA) from 2009 to 2018 to determine which cosmetic allergens produce a high yield of contact allergy. Contact allergens with a prevalence of >0.3% that were considered relevant were included. Rare contact allergens were excluded if deemed no longer relevant or added to a supplemental cosmetic series for further analysis. RESULTS: Sensitization prevalences of 39 cosmetic contact allergens were tabulated. Thirty of these allergens yielded >0.3% positive reactions and are therefore included in our proposed European cosmetic series. Six were considered no longer relevant and therefore excluded. Three were included in a supplementary European cosmetic series. An additional nine allergens were included in either the core or supplemental European cosmetic series following literature review. CONCLUSION: We have derived a potential European cosmetic series based upon the above methods. This will require ongoing investigation based upon the changing exposure profiles of cosmetic allergens as well as new and evolving substances.

Patch testing 101, part 1: performing the test.

Understanding the basics of patch testing is essential to caring for patients with contact dermatitis. Several screening or standard series are available, and additional allergens or series may be necessary based on the patient's history. A delayed reading should be performed 72 to 144 hours after patch placement. Certain oral medications, phototherapy, or topical products may interfere with patch test results.

Thoughts on the interpretation of positive photopatch test reactions.

BACKGROUND: Positive photopatch test reactions are classified according to the International Contact Dermatitis Group. The various reaction patterns are interpreted to represent patterns such as contact allergy, photocontact allergy, photoaugmentation, and photoinhibition. OBJECTIVE: To investigate whether there are any weaknesses in the interpretation of reaction patterns. MATERIALS & METHODS: A dermatitis patient with photoallergic contact dermatitis due to ketoprofen was photopatch tested with serial dilutions of ketoprofen in ethanol. The reaction patterns for the various concentrations were used as a basis for discussion on weaknesses regarding the present interpretations of positive photopatch test reactions. RESULTS: The reaction patterns to the ketoprofen photopatch at various concentrations were interpreted as (i) contact allergy, (ii) contact allergy with photoaugmentation, (iii) contact allergy and photocontact allergy, and (iv) photocontact allergy. CONCLUSION: The present interpretation of positive photopatch test reactions is unreliable and therefore insufficient regarding appropriate advice for patients.

Patch Testing During the COVID-19 Pandemic: Recommendations of the AEDV's Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC). / Recomendaciones del Grupo Español de Investigación en Dermatitis de Contacto y Alergia Cutánea (GEIDAC) de la AEDV en relación con la realización de pruebas epicutáneas durante la pandemia por SARS-CoV-2 (COVID-19).

As the COVID-19 pandemic gradually comes under control, the members of the Spanish Contact Dermatitis and Skin Allergy Research Group (GEIDAC) have drawn up a proposed list of the requirements, limitations, and conditioning factors affecting the resumption of work in contact dermatitis units. The assumption is that the severe acute respiratory syndrome coronavirus2 is still circulating and that occasional or seasonal outbreaks will occur. They recommend that the first step should be to assess how many patch tests each clinic can handle and review the waiting list to prioritize cases according to disease severity and urgency. Digital technologies can, where possible, be used to send and receive the documentation necessary for the patch test (information, instructions, informed consent, etc.). If the necessary infrastructure is available, patients can be offered the option of a remote initial consultation. Likewise, in selected cases, the patch test results can be read in a virtual visit using photographs taken by the patient or a video visit can be scheduled to allow the physician to evaluate the site of application remotely. These measures will reduce the number of face-to-face visits required, but will not affect the time spent on each case, which must be scheduled in the normal manner. All of these recommendations are suggestions and should be adapted to the needs and possibilities of each health centre.

Quantification of aluminium release from Finn chambers under different in vitro test conditions of relevance for patch testing.

BACKGROUND: Contact allergy to aluminium (Al) might pose a risk of false-positive readings of patch-test results when testing with Finn chambers. OBJECTIVES: To quantify the release of Al from empty Al Finn chambers, covered Finn Aqua chambers, and Al Finn chambers containing different baseline patch-test substances. METHODS: Al Finn chambers of different conditions and with different patch-test substances were tested in artificial sweat and their Al release was analyzed by atomic absorption spectroscopy and inductively coupled plasma sector field mass spectrometry. RESULTS: The amount of Al released from empty Finn chambers corresponded to a skin dose of 0.03%-0.5% Al chloride hexahydrate applied in plastic chambers. Although most patch-test substances reduced the release of Al from the Finn chambers due to covering the surface, some substances significantly increased the release of Al from the Finn chambers, most notable for Caine mix II 10% pet., Myroxylon pereirae 25% pet., and sodium tetrachloropalladate hydrate 3.0% pet. CONCLUSIONS: The release of Al from Finn chambers corresponds in some cases to clinically relevant concentrations of Al for Al-sensitized individuals.

American Contact Dermatitis Society Allergens of the Year 2000 to 2020.

Allergic contact dermatitis is a delayed type IV hypersensitivity skin reaction to external stimuli. Patterns of dermatitis depend on allergen exposure and patch testing is the gold standard to identify causal agents. The American Contact Dermatitis Society identifies an "Allergen of the Year" in order to highlight facts about particular allergens, which may range from showing increasing prevalence of disease, to documenting low levels of relevant allergic reactions. This article reviews the allergens of the year from 2000 to 2020 with an emphasis on clinical relevance. Categories of allergens include adhesives, dyes, medications, metals, preservatives, rubber accelerators, surfactants, and other skin care product ingredients.

Safety Checks in Patch Clinic: 5 Hurdles in the Patch Testing Obstacle Course.

Accuracy in patch testing is critical for correct allergen identification. This multistep process is prone to error and risk increases with more staff (physicians, residents, fellows, technicians), antigens, and patients. Standardized safety checkpoints increase efficiency, consistency, and safety. In this article, we outline workflows developed for 20 years of experience, which maximize productivity and communication among team members to minimize system errors. We organize patch safety into 5 key "hurdles," or steps, and outline the specific safety procedures of each step via the use of checklists, easy visual cues, and double verification. The 5 hurdles include the following: (a) inventory (stocking sufficient antigens, maintaining chemical viability through appropriate storage, systematizing correct antigen identification); (b) patch preparation (consistent order communication, standardizing conformation and numbering of patches, accurate placement of antigens on patches); (c) application (maximizing patch contact with suitable skin on patient, minimizing risk of interference with patch test reactions); (d) documentation (accurate maps, avoiding "frame shift" misreads); and (e) education (promoting patient partnership, allergen avoidance).

Patch Test Clinic Start-up: From Basics to Pearls.

Allergic contact dermatitis is a prevalent burdensome condition affecting millions of Americans. Patch testing, the criterion-standard allergic contact dermatitis diagnostic tool, is underused by US dermatologists. Incorporating patch testing into modern dermatology practices is achievable with utilization of accurate resources and sustainable support. This review focuses on the basics of patch testing and provides practical pearls to assist novice providers in establishing a contact dermatitis specialty practice.

A seven-year retrospective analysis of patch test data in a cohort of patients with contact dermatitis in Sri Lanka.

BACKGROUND: Patch testing with a baseline series is a common tool employed when the sensitizing agent in contact dermatitis is unclear. However, for Asian countries, there are no locally validated baseline series to utilize in screening. METHODS: We completed a retrospective analysis of all patients that had undergone patch testing with the European Baseline series, Shoe Series or Comprehensive International Baseline series, over 7 years from 2012 to 2018 in a tertiary care reference dermatology clinic in Sri Lanka to evaluate the suitability of these investigations to identify causes for contact dermatitis in the local study population. RESULTS: Out of 438 patients tested, 239 (54.8%) reacted to at least one substance in the series. The Shoe Series was significantly more likely to yield a positive result than the European Baseline Series (70.2% vs 46.9%, p < 0.05). The top three sensitizers identified by all series were nickel sulfate (16%, 70/438), p-phenylenediamine (12.3%, 54/438) and 2-mercaptobenzothiazole or mercapto mix (10.5%, 46/438). CONCLUSION: Shoe series has a comparatively high yield in the local population compared to European Baseline series. Since little less than half of the study population did not have any reactivity to any of the allergens tested it is important to develop or modify and validate a locally relevant, more suitable baseline series which is based on the Shoe Series in Sri Lanka. This is further evidence for the continuously changing nature of allergens in the environment and the need to modify existing patch testing standards accordingly.