About

Margo Reeder MD is an Associate Professor and Medical Director of General Dermatology at the Department of Dermatology, UW–Madison. She completed her Bachelor of Science in Biology with a minor in Environmental Studies at the University of Wisconsin, Madison in 2004, and earned her Doctor of Medicine degree from Mayo Medical School in 2009. She completed her Dermatology Residency Program at the University of Wisconsin Hospitals and Clinics in 2013, following an internship in the Transitional Year Residency Program at the University of South Dakota in 2010. Her research focuses on clinical research, including clinical database development, quality improvement, and the implementation of outcome measures for clinical practice. She has contributed to the field through her work on contact dermatitis, allergen management, and the safety of dermatological products. Dr. Reeder is a member of several professional organizations, including the American Academy of Dermatology, the American Contact Dermatitis Society, and the Wisconsin Dermatological Society.

Research topics

• Medicine
• Dermatology
• Immunology
• Pathology
• Computer Science
• Advertising
• Paleontology
• Database
• Geology
• Business
• Process engineering
• Internal medicine
• Engineering
• Organic chemistry

Selected publications

• Patch Test Reactions Associated with Food Sources: A Retrospective Analysis of the North American Contact Dermatitis Group Data (2001–2018)

  Dermatitis · 2026-03-02

  article

  Abstract: Background: Contact dermatitis due to food exposure is underrecognized. Objectives: To characterize relevant allergens associated with food sources and analyze patient and clinical characteristics associated with food-related allergen exposure in patients with a currently relevant positive patch test reaction (PPTR). Methods: We retrospectively analyzed North American Contact Dermatitis Group data from 2001 to 2018, identifying relevant allergens linked to food sources. Patients with currently relevant PPTRs were divided into food-related and non-food-related exposure groups for comparison. Results: Among 43,722 patients, 867 (2.0%) had at least one currently relevant food-related PPTR, accounting for 936 PPTR reactions. The most common allergens were nickel (411, 43.9%), Balsam of Peru (BOP, 287, 30.7%), and fragrance mix 1 (FM1, 60, 6.4%). Carvone (24/139 [17.3%]) and sodium metabisulfite (10/87 [11.5%]) showed the highest food-related proportions. Among 867 food-related patients, the most commonly affected areas were generalized (30.22%) and the hand (19.26%). Patients having food-related PPTR were significantly less likely to involve the hand (OR, 0.59; P < 0.0001) and face (OR, 0.43; P < 0.0001) as compared with nonfood-related patients. Food exposure was associated with a higher likelihood of anogenital dermatitis ( P ≤ 0.01 for nickel sulfate, BOP or FM1). Conclusion: Nickel, BOP, and FM1 were the most common food-related allergens. Common sites of dermatitis in patients with food-related PPTR were generalized, anogenital areas, and hands, although involvement of the hands and face was significantly less likely compared with nonfood-related cases.

  PublisherDOI

• Occupational contact dermatitis in North American health care workers: Trends and triggers (2005-2022)

  Journal of the American Academy of Dermatology · 2026-03-01

  article1st authorCorresponding
  PublisherDOI

• Comparison Between Brazilian Propolis and Chinese Propolis: Results From the North American Contact Dermatitis Group 2019–2022

  Dermatitis · 2025-12-05 · 1 citations

  articleOpen access

  Abstract: Background: Prevalence of positive patch test (ppt) reactions to propolis in Europe has varied with different allergen source origins. Compared with previous cycles, the North American Contact Dermatitis Group (NACDG) noted a marked increase in propolis positivity in 2019–2020. Objective: To compare propolis positivity in North American centers between 3 periods (2019, 2020, and 2021/2022), based on geographic origin and supplier. Methods: Retrospective analysis of NACDG patch test data (2019–2022) utilizing 3 different sources of propolis: Chinese propolis (Allergeaze—CPA), Chinese propolis (Chemotechnique—CPC), and Brazilian propolis (Allergeaze—BPA). Results: Proportions of ppt reactions to propolis were: 3.7% (84/2260) to CPA in 2019, 14.7% (271/1838) to BPA in 2020, and 2.2% (66/3052) to CPC in 2021/2022. There was a statistically significant difference in prevalence of reactions for BPA compared with both CPA and CPC ( P < 0.00001). Conclusions: When unexpected changes are noted in patch test positivity, especially with naturally derived allergens, the reasons behind those changes should be investigated. The substitution of Brazilian for Chinese propolis resulted in a significant increase in ppt reactions.

  PublisherDOI

• Consensus on core domains for hand eczema trials: Signs, symptoms, control and quality of life

  Journal of the European Academy of Dermatology and Venereology · 2025-04-25 · 3 citations

  articleOpen access

  BACKGROUND: Hand eczema (HE) is a common and complex skin disease. A uniform set of core outcomes and related measures for use in clinical trials is lacking, making it difficult to compare results across HE studies. OBJECTIVE: To reach consensus on a set of core domains and subdomains that should be measured in future therapeutic HE trials. METHODS: In 2024, we conducted a two-round online Delphi (eDelphi) survey among international HE experts, including physicians, patients and their relatives, researchers and industry representatives. A domain/subdomain was included in the core set when ≥80% of participants rated is as 'critically important'; 50% agreement or less resulted in its exclusion. Results from 50% to 80% were deemed controversial and subject for further discussion. During a hybrid consensus meeting, the stakeholders reviewed, completed and, if necessary, revised the preliminary eDelphi consensus. RESULTS: In the first and second round of the eDelphi, 208 and 134 persons, respectively, participated. Forty participants from 18 countries attended the consensus meeting. Consensus was reached to include the core domains 'signs of HE' (with five core subdomains), 'symptoms of HE' (two subdomains), 'HE-related quality of life' (four subdomains) and 'HE control over time' (four subdomains). The subdomains 'desquamation/scaling' and 'emotional impact/mental health' remained controversial. Consensus was reached that the domains 'skin barrier function' and 'patient-reported treatment experience' and 28 subdomains should not be part of the core outcome set. CONCLUSIONS: To produce comparable and meaningful results, future trials evaluating the effectiveness of HE treatments should measure signs and symptoms of HE, HE-related quality of life and HE control over time as core outcome domains. The next step of the HE core outcome set initiative (HECOS) is to identify appropriate measurement instruments.

  PublisherOA PDFDOI

• North American Contact Dermatitis Group Patch Test Results: 2021–2022

  Dermatitis · 2025-04-24 · 16 citations

  article

  Abstract: Background: Patch testing is an important diagnostic tool for the assessment of allergic contact dermatitis (ACD). Objective: This study documents the North American Contact Dermatitis Group (NACDG) patch testing results from 2021 to 2022. Methods: At 12 centers in North America, patients were tested in a standardized manner with a screening series of 80 allergens. Results: Overall, 3056 patients were tested; 2200 (72.0%) had at least 1 positive/allergic patch test reaction and 1412 patients (46.6%) had a primary diagnosis of ACD. The most commonly positive allergens were nickel sulfate hexahydrate 5% and 2.5% petrolatum (24.9% and 22.1%, respectively), methylisothiazolinone (MI) (11.5%), hydroperoxides of linalool (10.1%), cobalt chloride hexahydrate (9.2%), and methylchloroisothiazolinone/methylisothiazolinone (9.0%). Compared with 2019–2020, prevalence of the top 20 allergens statistically increased for nickel ( P < 0.001), cobalt ( P < 0.01), gold ( P < 0.001), hydroperoxides of limonene ( P < 0.001), oleamidopropyl dimethylamine ( P < 0.01), dimethylaminopropylamine ( P < 0.01), and ammonium persulfate ( P < 0.001). MI positivity continued to decrease from its peak in 2017–2018. More than one-fifth of patients (n = 640, 21.1%) had at least one clinically relevant reaction to an allergen/substance not present in the NACDG screening series. Conclusions: The epidemic of MI contact allergy in North America appears to continue its descent. Fragrance allergy is still very common, but the composition of fragrance allergy markers appears to be changing. Patch testing using a robust screening series, and supplemental allergens as indicated, is necessary for the comprehensive evaluation of ACD.

  PublisherDOI

• Not Just Pink Eye: Allergic Contact Dermatitis to Alcaftadine 0.25% Ophthalmic Solution

  Contact Dermatitis · 2025-06-29

  articleOpen accessSenior authorCorresponding

  Periorbital dermatitis is frequently due to allergic contact dermatitis (ACD) and patients describe symptoms of swelling, itch, and redness on the eyelids and surrounding skin [1]. Common causative allergens include metals, preservatives, fragrances, and acrylates, whereas common sources include cosmetics and other personal care products, jewellery and nail products [1-3]. Additionally, allergens in topical medications, mainly eye drops and antibiotics, have been recognised as important precipitants of periorbital ACD [1-5]. Patient 1 (64-year-old female) with a history of Sjögren's syndrome with keratoconjunctivitis sicca and corneal scar of the left eye presented with a 4-year history of intermittent periorbital redness and swelling (Figure 1a). Patient 2 (50-year-old female) with a history of Sjögren's syndrome presented with a 4-month history of recurrent eyelid dermatitis described as itchy, scaly and red. Patient 3 (38-year-old female) with a history of bilateral retinal lattice degeneration and prior retinal surgeries presented with a 6-month history of recurrent periorbital dermatitis associated with itching, swelling and conjunctival injection (Figure 1c). All patients were using alcaftadine 0.25% solution (Lastacaft) drops and other eye care products for several months to years (Table 1). Patch testing was performed using a standard technique with Finn Chambers (SmartPractice, Phoenix) on Scanpor tape (Norgesplaster Alpharma AS Vennesla, Norway) and included the North American Contact Dermatitis Group (NACDG) screening series, an expanded cosmetic series, and custom patches to the patients' eye drops and relevant eye care products. The skin was gently scratched prior to the application of eyedrops as previously described [7]. All three patients tested positive (+, Figure 1b,d) to Lastacaft (ingredients: benzalkonium chloride, edetate disodium, monobasic sodium phosphate, purified water, sodium chloride, sodium hydroxide, hydrochloric acid) and negative to benzalkonium chloride and other eye products at days 4 and 5 (Table 1). Of the two patients with clinical follow-up, both showed improvement with discontinuation of Lastacaft drops. Standard Supplemental Cosmetic Plants Corticosteroids Standard Supplemental Cosmetic Standard Supplemental Cosmetic Lastacaft (alcaftadine 0.25%), antihistamine drops Lotemax (loteprednol 0.5%), corticosteroid gel Systane, lubricant drops Blink, lubricant drops Boston, rewetting drops Fluorometholone, cortiscosteroid drops Prednisolone, corticosteroid drops Lastacaft (alcaftadine 0.25%), antihistamine drops Restasis (cyclosporine 0.05%) drops Lotemax (loteprednol 0.5%), corticosteroid gel Refresh, lubricant drops OCuSOFT, eyelid cleanser Lastacaft (alcaftadine 0.25%), antihistamine drops Biotrue, moisturising drops Potassium dichromate 0.25% (pet): + (UR) Benzisothiazolinone 0.1% (pet): + (UR) Fragrance mix I 8.0% (pet): + (CR) Lauryl glucoside 3.0% (pet): + (CR) decyl glucoside 5.0% (pet): + (CR) Alcaftadine, the active ingredient in Lastacaft, is primarily a H1 histamine receptor antagonist and mast cell stabiliser. It is available in the United States as an over-the-counter medication and is commonly used in the treatment of itching associated with allergic conjunctivitis. Prior to this report, only one case of ACD to alcaftadine 0.25% solution had been described [8]. Ketotifen and olapatadine are other antihistamines used as active ingredients in eyedrop solutions and have also been reported to cause ACD [9, 10]. Antihistamine eye drops are used to treat allergic conjunctivitis and ACD to these agents can present with similar symptoms, such as itching, swelling, and redness, delaying timely recognition and treatment. This report highlights the importance of considering patients' ophthalmic products as causes of periorbital dermatitis. Custom patch testing to these products can help identify novel allergens, such as alcaftadine, that are not included in a standard series and would otherwise be missed as important allergens. Mayra Betancourt Ponce: conceptualization, writing – original draft, investigation, writing – review and editing. Margo Reeder: writing – review and editing, investigation, methodology, validation, supervision, conceptualization. All patients provided written informed consent for the use of their photographs in this manuscript. Consent was obtained in accordance with institutional guidelines and ethical standards for publication. The authors declare no conflicts of interest.

  PublisherOA PDFDOI

• Comparing Home vs Office-Based Phototherapy for the Treatment of Psoriasis: The LITE Study

  2025-10-31

  report
  PublisherDOI

• Updated expert opinion guidelines regarding the effects of immunosuppressive agents on patch testing

  Journal of the American Academy of Dermatology · 2025-02-03 · 1 citations

  article
  PublisherDOI

• Home- vs Office-Based Narrowband UV-B Phototherapy for Patients With Psoriasis

  JAMA Dermatology · 2024-09-25 · 22 citations

  articleOpen access

  Importance: Office-based phototherapy is cost-effective for psoriasis but difficult to access. Home-based phototherapy is patient preferred but has limited clinical data, particularly in patients with darker skin. Objective: To compare the effectiveness of home- vs office-based narrowband UV-B phototherapy for psoriasis. Design, Setting, and Participants: The Light Treatment Effectiveness study was an investigator-initiated, pragmatic, open-label, parallel-group, multicenter, noninferiority randomized clinical trial embedded in routine care at 42 academic and private clinical dermatology practices in the US. Enrollment occurred from March 1, 2019, to December 4, 2023, with follow-up through June 2024. Participants were 12 years and older with plaque or guttate psoriasis who were candidates for home- and office-based phototherapy. Interventions: Participants were randomized to receive a home narrowband UV-B machine with guided mode dosimetry or routine care with office-based narrowband UV-B for 12 weeks, followed by an additional 12-week observation period. Main Outcomes and Measures: The coprimary effectiveness outcomes were Physician Global Assessment (PGA) dichotomized as clear/almost clear skin (score of ≤1) at the end of the intervention period and Dermatology Life Quality Index (DLQI) score of 5 or lower (no to small effect on quality of life) at week 12. Results: Of 783 patients enrolled (mean [SD] age, 48.0 [15.5] years; 376 [48.0%] female), 393 received home-based phototherapy and 390 received office-based phototherapy, with 350 (44.7%) having skin phototype (SPT) I/II, 350 (44.7%) having SPT III/IV, and 83 (10.6%) having SPT V/VI. A total of 93 patients (11.9%) were receiving systemic treatment. At baseline, mean (SD) PGA was 2.7 (0.8) and DLQI was 12.2 (7.2). At week 12, 129 patients (32.8%) receiving home-based phototherapy and 100 patients (25.6%) receiving office-based phototherapy achieved clear/almost clear skin, and 206 (52.4%) and 131 (33.6%) achieved DLQI of 5 or lower, respectively. Home-based phototherapy was noninferior to office-based phototherapy for PGA and DLQI in the overall population and across all SPTs. Home-based phototherapy, compared to office-based phototherapy, was associated with better treatment adherence (202 patients [51.4%] vs 62 patients [15.9%]; P < .001), lower burden of indirect costs to patients, and more episodes of persistent erythema (466 of 7957 treatments [5.9%] vs 46 of 3934 treatments [1.2%]; P < .001). Both treatments were well tolerated with no discontinuations due to adverse events. Conclusions and Relevance: In this randomized clinical trial, home-based phototherapy was as effective as office-based phototherapy for plaque or guttate psoriasis in everyday clinical practice and had less burden to patients. Trial Registration: ClinicalTrials.gov Identifier: NCT03726489.

  PublisherOA PDFDOI

• Nonmedical Adhesive Allergens: Retrospective Analysis of Cross-Sectional Data from the North American Contact Dermatitis® Group, 2001–2018

  Dermatitis · 2024-04-09 · 1 citations

  letter
  PublisherDOI

Frequent coauthors

• Joel G. DeKoven

  Sunnybrook Health Science Centre

  178 shared

• Erin M. Warshaw

  177 shared

• Amber Reck Atwater

  Eli Lilly (United States)

  110 shared

• Denis Sasseville

  McGill University Health Centre

  94 shared

• Vincent A. DeLeo

  University of Southern California

  76 shared

• Jonathan I. Silverberg

  74 shared

• Melanie D. Pratt

  72 shared

• D. Belsito

  Columbia University Irving Medical Center

  69 shared

Labs

• Reeder LaboratoryPI

Education

• B.S., Biology, Minor Environmental Studies

  University of Wisconsin, Madison, WI

  2004

• M.D.

  Mayo Medical School, Rochester, MN

  2009

• Other

  Certification in Dermatology

  2013

• Other

  Dermatology Residency Program, University of Wisconsin Hospitals and Clinics, Madison, WI

  2013

• Other

  Transitional Year Residency Program, University of South Dakota, Sioux Falls, SD