Hall, Matthew R.

Radiology plays an integral role in guiding management of dermatologic disease and allows evaluation deep to the skin, determination of subcutaneous extent and spread, pretreatment detection of metastatic nodal disease, and posttreatment detection of persistence, recurrence, or unexpected complications.

Background Delivery of dermatologic care through telemedicine was accelerated by the COVID-19 pandemic. We sought to analyze the teledermatology experience across Mayo Clinic's health care system to identify strengths and limitations of teledermatology. Methods Electronic health records of dermatology televisits were reviewed from multiple U.S. Mayo Clinic sites from January 2020 through January 2021. Results A total of 13,181 dermatology televisits were conducted in 6468 unique patients. Patients were primarily female (60.2%), and mean age of all patients was 34.1 years. Synchronous / live video conferencing visits were the most common (40.0%) telecare modality. Synchronous / live audio conferencing and asynchronous / store-and-forward visits comprised 33.0% and 27.0% of appointments. In total, 3944 televisits (29.9%) were successfully concluded via a single appointment. An in-person appointment was needed for 1693 patients (26.2%) after their initial televisit. For patients with a single televisit, synchronous / live video conferencing was the most common virtual modality (58.0% vs 32.2% of patients with multiple visits, p < 0.001). Patients needing in-person follow-up visits were slightly older than those who did not (mean [SD], 38.8 [22.3] vs 35.0 [23.6] years; p < 0.001) but without any sex-based difference. Around one-third of patients needed an in-person follow-up visit after their initial asynchronous / store-and-forward visit which was higher when compared with synchronous / live audio and video conferencing. Conclusion Single dermatology televisits effectively managed nearly one-third of patients who did not require in-person follow-up. An initial synchronous / live video conferencing was more likely to yield a single clinical encounter, whereas asynchronous / store-and-forward visits required more in-person follow-up. Future studies are required that focus on dermatology-specific cost, diagnoses, access, quality of care, and outcomes.

ImportancePatients are frequently copositive for multiple allergens simultaneously, either due to chemical similarity or simultaneous sensitization. A better understanding of copositivity groups would help guide contact avoidance.ObjectiveTo use patient data to systematically determine copositivity groups in the Mayo Clinic Standard Series.Design, Setting, and ParticipantsIn this retrospective cross-sectional analysis, the Mayo Clinic patch test database was queried for pairwise copositivity rates in the 80 allergen Mayo Clinic Standard Series between 2012 and 2021. Data were collected from 3 tertiary care sites of the Mayo Clinic Contact Dermatitis Group and a total of 5943 patients were included, comprising all patients undergoing patch testing to the Mayo Clinic Standard Series allergens.Main Outcomes and MeasuresCopositivity rates between every 2 allergens in the 80-allergen Mayo Clinic Standard Series were estimated. After background correction, copositivity rates were analyzed using unsupervised hierarchical clustering to systematically identify copositivity groups in an unbiased manner.ResultsOverall, 394 921 total patches were applied to 5943 patients (4164 [70.1%] women, 1776 [29.9%] men, with a mean [SD] age of 52.3 [18.8] years ), comprising 9545 positive reactions. After background correction based on overall positivity rates, hierarchical clustering revealed distinct copositivity groups. Many were supported by prior literature, including formaldehyde releasers, cobalt-nickel-potassium dichromate, acrylates, 3-dimethylaminopropylamine-amidoamine-oleamidopropyl dimethylamine, alkyl glucosides, budesonide-hydrocortisone-17-butyrate, certain fragrances, compositae-sesquiterpene lactone mix, mercapto mix-mercaptobenzothiazole, carba mix-thiuram mix, and disperse orange-p-phenylenediamine. However, novel associations were also found, including glutaraldehyde-sorbitan sesquioleate, benzalkonium chloride-neomycin-bacitracin, bronopol-methylchloroisothiazolinone-methylisothiazolinone, and benzoic acid-iodopropynyl butylcarbamate.Conclusions and RelevanceThis retrospective cross-sectional analysis found that copositivity rates varied between allergens; allergens with extremely high positivity rates demonstrated nonspecific copositivity to multiple other allergens. Background correction based on positivity rates followed by hierarchical clustering confirmed prior known copositivity groups, contaminants and/or excipients leading to copositivity, and novel associations to guide contact avoidance.

Importance Individuals with allergic contact dermatitis to one topical corticosteroid may also react to other corticosteroids. Corticosteroid classification models have been proposed to predict such copositivity, recommend representative screening corticosteroids, and guide allergen avoidance. Objective To use patient data to determine copositivity patterns between corticosteroids and evaluate against previous corticosteroid classification models. Design, Setting, and Participants This qualitative study included a retrospective analysis of the Mayo Clinic Contact Dermatitis Group corticosteroid patch test data from 2010 to 2019. Among patients undergoing patch testing with the Mayo Clinic’s standard or steroid series who consented to research participation, 5637 patients were included in the analysis. Copositivity rates were determined between corticosteroids and analyzed by hierarchical clustering for comparison to previous classification models. Main Outcomes and Measures The frequency of patch test positivity to each of the analyzed corticosteroids was noted and compared with previously published patch test positivity rates. Copositivity rates between each pair of corticosteroids were determined, and overall copositivity patterns were analyzed and evaluated against known steroid classes. Results A total of 49 472 individual patches were applied to 5637 patients, testing 18 corticosteroids. Patch test positivity rates ranged between 0.3% and 4.7%. The fluocinonide positivity rate corresponded to the highest copositivity rate with other corticosteroids (mean [SD], 50.7% [26.1%]). Tixocortol-21-pivalate, 0.1%, and tixocortol-21-pivalate, 1%, positivity rates corresponded to the lowest copositivity rates (mean [SD], 4.1% [1.7%] and 3.6% [1.4%], respectively). Hierarchical clustering elucidated patterns that did not support previous corticosteroid classification models. Conclusions and Relevance In this qualitative study, copositivity rates were variable between corticosteroids, and overall patch test positivity for allergy to topical corticosteroids was rare. Previously published corticosteroid classifications are not supported by real patient-derived data and may not be accurate in predicting corticosteroid copositivity.

Background A major question in patch testing is when to perform the final reading. Our current standard practice is to place patches on day 1, remove them on day 3, and perform readings on days 3 and 5. For certain allergens, another reading is performed sometime from days 7 to 14≥. Objectives The aim of the study was to identify allergens with positive reactions on day 5 that were negative on day 7 or later and allergens with negative reactions on day 5 that were subsequently positive on day 7 or later. Methods We reviewed records of patients who underwent patch testing from January 2007 to December 2016 at Mayo Clinic with readings on day 5 and day 7 or later. Conclusions In total, 131 allergens had positive reactions on day 5 that were negative on day 7 or later, and 58 allergens had negative reactions on day 5 that were positive on day 7 or later. Twenty-five allergens had significantly higher reaction rates on day 5 than day 7 or later. Our standard practice is to perform readings on days 3 and 5 and on days 3, 5, and 7 or later for series containing metals. Readings on days 3, 5, and 7 or later should also be considered for acrylates.

Background Patch testing to a standard (baseline) series of allergens is the screening tool used to identify culprit allergens in patients with contact dermatitis. The allergens and concentrations used in a standard series are constantly evolving to be most relevant to the patients being patch tested. Objective The aim of this study was to analyze the 2011–2015 patch test results of the Mayo Clinic standard series. Methods We retrospectively reviewed patch test reactions of standard series allergens from 2011 through 2015 and compared these results with the 2011–2012 and 2013–2014 North American Contact Dermatitis Group (NACDG) reports. Conclusions Of 2582 patients included, 1566 (60.7%) had at least 1 positive reaction, and 516 (20.0%) had at least 1 irritant reaction. The 15 allergens with the highest reaction rates (from highest to lowest) were nickel sulfate hexahydrate, methylisothiazolinone, Myroxylon pereirae resin, neomycin sulfate, cobalt (II) chloride hexahydrate, benzalkonium chloride, fragrance mix I, potassium dichromate, bacitracin, methylchloroisothiazolinone/methylisothiazolinone, carba mix, formaldehyde, p -phenylenediamine, quaternium-15, and methyldibromo glutaronitrile. Twelve (80%) of these allergens were also in the top 15 of the most recent NACDG report; the 3 allergens not in the NACDG top 15 allergens were potassium dichromate, benzalkonium chloride, and methyldibromo glutaronitrile (the latter 2 allergens are not included in their series).

Background Patch-test readings after day 5 have previously been used to identify delayed reactions to metals and topical antibiotics. Objective The aims of this study were to identify allergens for which late readings (beyond day 5) would be most valuable and to compare our results with our previous study on delayed patch-test readings. Methods This was a retrospective study of 298 patients who underwent metal and corticosteroid series patch testing from January 1, 2007, through December 31, 2013. Patch-test readings were conducted on days 3 and 5 and at least once sometime between days 7 and 14. All reactions were examined at each reading. Conclusions These results were concordant with our previous findings that additional readings after day 7 are particularly useful for identifying reactions to metals (gold, cobalt, beryllium, palladium), specific preservatives (dodecyl gallate, propolis), and the topical antibiotic neomycin. New delayed reactions to bacitracin, p -phenylenediamine, and topical corticosteroids were not seen in this cohort.