Teledermatology in practice: Report of Mayo Clinic experience.

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.

Pediatric Patch Testing at Mayo Clinic Between 2016 and 2020.

Background: Allergic contact dermatitis (ACD) is a common condition within the pediatric population. Patch testing is an important way to identify relevant allergens. Objective: To provide an update of the common contact allergens seen in children based on patch testing data at our institution from 2016 to 2020. Methods: We performed a retrospective analysis of patch test data from children aged 1-18 years from 2016 to 2020 at Mayo Clinic. Reaction rates were compared to the rates reported by the Pediatric Contact Dermatitis Registry (PCDR). Results: One hundred ninety-two children aged 1-18 were patch tested to various allergens. A total of 15,457 allergens were tested, with 291 positive tests. The top 5 allergens with highest positive reaction rates were hydroperoxides of linalool, hydroperoxides of limonene, methylisothiazolinone, nickel, and cobalt. Seven of the top 38 allergens with the highest reaction rates are not currently included in the Mayo Clinic Pediatric Patch Test Series, and 11 are not currently included in the Pediatric Baseline Series (as developed by the Pediatric Contact Dermatitis Workgroup). Conclusions: Patch testing is a useful tool to diagnose children with ACD. With new products and exposures, there is an opportunity to expand current pediatric patch testing series.

Results of Patch Testing to Botanicals: Review of the Mayo Clinic Experience Over 2 Decades (1997-2017).

Background: Botanicals are increasingly incorporated into skincare products. Although allergic contact dermatitis due to botanicals is recognized, data describing the prevalence of positive patch tests to botanicals are sparse. Objective: To report the Mayo Clinic experience of patch testing to selected botanical products in the standard, extended standard, fragrance, and plant series. Methods: IRB-approved retrospective study of the Mayo Clinic experience with patch testing to botanicals from 1997 to 2017. Results: In total, 12,169 people were patch tested to botanicals in the standard, extended standard, fragrance, and plant series; 4032 were men and 8137 were women. The mean age of the population tested was 54 (standard deviation 17.7) years. Almost 11% (1320/12,169) of the patch-tested population exhibited positive reactions to at least 1 botanical agent. Myroxylon pereirae resin 25% was the most common positive allergen in the series. Patients who had positive reactions to at least 1 botanical agent were more (19.8%) likely to have a positive reaction to at least 1 additional botanical than those patients who did not have any positive tests. Most patients presented with generalized involvement (334) or involvement of the hands (284) or face (232). Conclusion: Physicians should be aware of the high prevalence of allergic contact dermatitis and patch test positivity associated with botanical products.

Systematic Identification of Copositivity Groups in Standard Series Patch Testing Through Hierarchical Clustering.

Importance: Patients 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. Objective: To use patient data to systematically determine copositivity groups in the Mayo Clinic Standard Series. Design, Setting, and Participants: In 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 Measures: Copositivity 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. Results: Overall, 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 Relevance: This 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.

Trends in Patch Testing With the Mayo Clinic Standard Series, 2017-2021.

Background: Patch testing to a standard series is used to identify culprit allergens in patients with contact dermatitis. The reaction rates evolve over time based on trends in cutaneous exposures by the general population. Objective: The aim of this study was to analyze the patch test results of the Mayo Clinic standard series in patients tested from 2017 to 2021. Methods: The patch test reactions of standard series allergens tested from 2017 to 2021 were retrospectively reviewed and compared with the results of our prior report from 2011 to 2015 as well as the North American Contact Dermatitis Group (NACDG) report from 2017 to 2018. Results: Of 2667 patients tested, 1683 (63.1%) had at least 1 positive reaction. The 15 allergens with the highest reaction rates were hydroperoxides of linalool 1%, nickel (II) sulfate hexahydrate, methylisothiazolinone, Myroxylon pereirae resin, hydroperoxides of linalool 0.5%, methyldibromo glutaronitrile, neomycin sulfate, cobalt (II) chloride hexahydrate, fragrance mix I, benzalkonium chloride, bacitracin, hydroperoxides of limonene, methylchloroisothiazolinone/methylisothiazolinone, p-phenylenediamine, and textile dye mix. Twelve (80%) of these allergens were also in the top 15 of the most recent NACDG report. Conclusions: Hydroperoxides of linalool and hydroperoxides of limonene are new allergens that have been added to our standard series. These are associated with high reaction rates.

Reevaluating Corticosteroid Classification Models in Patient Patch Testing.

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.

Deep learning for dermatologists: Part II. Current applications.

Because of a convergence of the availability of large data sets, graphics-specific computer hardware, and important theoretical advancements, artificial intelligence has recently contributed to dramatic progress in medicine. One type of artificial intelligence known as deep learning has been particularly impactful for medical image analysis. Deep learning applications have shown promising results in dermatology and other specialties, including radiology, cardiology, and ophthalmology. The modern clinician will benefit from an understanding of the basic features of deep learning to effectively use new applications and to better gauge their utility and limitations. In this second article of a 2-part series, we review the existing and emerging clinical applications of deep learning in dermatology and discuss future opportunities and limitations. Part 1 of this series offered an introduction to the basic concepts of deep learning to facilitate effective communication between clinicians and technical experts.

Deep learning for dermatologists: Part I. Fundamental concepts.

Artificial intelligence is generating substantial interest in the field of medicine. One form of artificial intelligence, deep learning, has led to rapid advances in automated image analysis. In 2017, an algorithm demonstrated the ability to diagnose certain skin cancers from clinical photographs with the accuracy of an expert dermatologist. Subsequently, deep learning has been applied to a range of dermatology applications. Although experts will never be replaced by artificial intelligence, it will certainly affect the specialty of dermatology. In this first article of a 2-part series, the basic concepts of deep learning will be reviewed with the goal of laying the groundwork for effective communication between clinicians and technical colleagues. In part 2 of the series, the clinical applications of deep learning in dermatology will be reviewed and limitations and opportunities will be considered.

Kerogen nanoscale structure and CO2 adsorption in shale micropores.

Gas storage and recovery processes in shales critically depend on nano-scale porosity and chemical composition, but information about the nanoscale pore geometry and connectivity of kerogen, insoluble organic shale matter, is largely unavailable. Using adsorption microcalorimetry, we show that once strong adsorption sites within nanoscale network are taken, gas adsorption even at very low pressure is governed by pore width rather than chemical composition. A combination of focused ion beam with scanning electron microscopy and transmission electron microscopy reveal the nanoscale structure of kerogen includes not only the ubiquitous amorphous phase but also highly graphitized sheets, fiber- and onion-like structures creating nanoscale voids accessible for gas sorption. Nanoscale structures bridge the current gap between molecular size and macropore scale in existing models for kerogen, thus allowing accurate prediction of gas sorption, storage and diffusion properties in shales.

The Final Patch Test Read: Day 5 or Day >7?

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.

Acceleration of dolomitization by zinc in saline waters.

Dolomite (CaMg(CO3)2) plays a key role in the global carbon cycle. Yet, the chemical mechanisms that catalyze its formation remain an enigma. Here, using batch reactor experiments, we demonstrate an unexpected acceleration of dolomite formation by zinc in saline fluids, reflecting a not uncommon spatial association of dolomite with Mississippi Valley-type ores. The acceleration correlates with dissolved zinc concentration, irrespective of the zinc source tested (ZnCl2 and ZnO). Moreover, the addition of dissolved zinc counteracts the inhibiting effect of dissolved sulfate on dolomite formation. Integration with previous studies enables us to develop an understanding of the dolomitization pathway. Our findings suggest that the fluids' high ionic strength and zinc complexation facilitate magnesium ion dehydration, resulting in a dramatic decrease in induction time. This study establishes a previously unrecognized role of zinc in dolomite formation, and may help explain the changes in dolomite abundance through geological time.

Trends in Patch Testing With the Mayo Clinic Standard Series, 2011-2015.

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).

Patch Testing to Propylene Glycol: The Mayo Clinic Experience.

BACKGROUND: Propylene glycol (PG) is a solvent, vehicle, and humectant being used increasingly in a wide array of personal care products, cosmetics, and topical medicaments. Propylene glycol is a recognized source of both allergic and irritant contact dermatitis. OBJECTIVE: The aim of the study was to report incidence of positive patch tests to PG at Mayo Clinic. METHODS: We retrospectively reviewed records of all patients patch tested to PG from January 1997 to December 2016. RESULTS: A total of 11,738 patients underwent patch testing to 5%, 10%, or 20% PG. Of these, 100 (0.85%) tested positive and 41 (0.35%) had irritant reactions. Patients also tested to a mean of 5.6 concomitant positive allergens. The positive reaction rates were 0%, 0.26%, and 1.86% for 5%, 10%, and 20% PG, respectively, increasing with each concentration increase. The irritant reaction rates were 0.95%, 0.24%, and 0.5% for 5%, 10%, and 20% PG, respectively. CONCLUSIONS: Propylene glycol is common in skin care products and is associated with both allergic and irritant patch test reactions. Increased concentrations were associated with increased reactions.

Delayed Patch-Test Reading After 5 Days: An Update From the Mayo Clinic Contact Dermatitis Group.

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.

Ni Mg Mixed Metal Oxides for p-Type Dye-Sensitized Solar Cells.

Mg Ni mixed metal oxide photocathodes have been prepared by a mixed NiCl2/MgCl2 sol-gel process. The MgO/NiO electrodes have been extensively characterized using physical and electrochemical methods. Dye-sensitized solar cells have been prepared from these films, and the higher concentrations of MgO improved the photovoltage of these devices; however, there was a notable drop in photocurrent with increasing Mg(2+). Charge extraction and XPS experiments revealed that the cause of this was a positive shift in the energy of the valence band, which decreased the driving force for electron transfer from the NiO film to the dye and, therefore, the photocurrent. In addition, increasing concentrations of MgO increases the volume of pores between 0.500 and 0.050 µm, while reducing pore volumes in the mesopore range (less than 0.050 µm) and lowering BET surface area from approximately 41 down to 30 m(2) g(-1). A MgO concentration of 5% was found to strike a balance between the increased photovoltage and decreased photocurrent, possessing a BET surface area of 35 m(2) g(-1) and a large pore volume in both the meso- and macropore range, which lead to a higher overall power conversion efficiency than NiO alone.

Trends in patch-test results and allergen changes in the standard series: a Mayo Clinic 5-year retrospective review (January 1, 2006, to December 31, 2010).

BACKGROUND: Patch testing is essential for identification of culprits causing allergic contact dermatitis. OBJECTIVE: We sought to identify trends and allergen changes in our standard series during 2006 to 2010, compared with our previous report (2001-2005). METHODS: We conducted a retrospective review of patch-test results. RESULTS: A total of 3115 patients were tested with a mean of 73.0 allergens. Since our prior report, 8 allergens were added to the standard series; 14 were deleted. Significantly higher rates of allergic positive reaction were documented for carba mix, 3%, and Disperse Orange 3, 1%. Rates were lower for 10 allergens: neomycin sulfate, 20%; gold sodium thiosulfate, 0.5%; hexahydro-1,3,5-tris(2-hydroxyethyl)triazine, 1%; disperse blue 124, 1%; disperse blue 106, 1%; diazolidinyl urea, 1%; hexylresorcinol, 0.25%; diazolidinyl urea, 1% aqueous; 2-bromo-2-nitropropane-1,3-diol, 0.25%; and lidocaine, 5%. Many final patch-test readings for many allergens were categorized as mild reactions (erythema only). Overall allergenicity and irritancy rates declined significantly since our prior report. Results were generally comparable with those in a North American Contact Dermatitis Group report from 2005 to 2006. LIMITATIONS: This was a retrospective study; there is a lack of long-term follow-up. CONCLUSIONS: Since our previous report, our standard series composition has changed, and overall rates of allergenicity and irritancy have decreased. Notably, many final patch-test readings showed mild reactions.