About

Sara Hylwa, MD, is an Associate Professor in the Department of Dermatology at the University of Minnesota. Her role involves mentoring and teaching dermatology residents in both outpatient clinic and inpatient hospital settings, as well as delivering formal didactic lectures throughout the year. She is also involved in mentoring residents in academic writing, including research proposals and manuscripts. Her clinical research interests include contact dermatitis, medical dermatology, and hospital dermatology, with a focus on advancing understanding and treatment in these areas.

Research topics

• Medicine
• Dermatology
• Pathology
• Surgery
• Virology
• Immunology

Selected publications

• To Avoid or Not to Avoid: Cross‐Reactivity Between Fragrance and Common Botanicals

  Contact Dermatitis · 2026-02-06

  articleOpen access

  BACKGROUND: Fragrance allergy is difficult to define, with thousands of known fragrance-related compounds. Whether certain botanicals should be considered 'fragrance' and whether fragrance-allergic patients should avoid these ingredients remains unclear, with minimal published data on the topic. OBJECTIVES: This study aimed to evaluate whether there is cross-reactivity between fragrance and various botanicals commonly found in personal-care products, such as aloe, coconut oil and shea butter, among others. METHODS: A cohort of fragrance-allergic patients was identified using data from 2038 patients patch-tested at a tertiary referral centre from 2020-2024. Cross-reactivity rates to botanicals commonly found in personal-care products were calculated, and statistical significance was determined using Fisher's exact test. Cross-reactivity was defined as > 10% reaction incidence. RESULTS: In patients with fragrance allergy, there was no significant cross-reactivity to any of the investigated botanical compounds. CONCLUSIONS: The low concomitant rates of reaction between fragrance and the investigated substances suggest that patients allergic to fragrance do not need to avoid certain common botanicals. Many products contain these compounds, including ones marked as 'fragrance-free'. Dermatologists can safely reassure fragrance-allergic patients of the safety of many botanicals commonly used in personal-care products.

  PublisherOA PDFDOI

• Nothing New Under the Sun?: Sunflower Oil Shows No Cross‐Reactivity With Nickel or Compositae Allergens

  Contact Dermatitis · 2025-06-24 · 1 citations

  articleOpen access

  Sunflower oil (Helianthus Annuus (Sunflower) Seed Oil, INCI) is a common emollient in personal care products. As a member of the Compositae plant family and a seed high in nickel content, its potential relevance for patients allergic to Compositae or nickel is of clinical interest. This study aimed to assess patch test reactivity to sunflower oil and examine potential sensitisation to these two allergens. We retrospectively reviewed 568 patients patch-tested with sunflower oil at our tertiary referral clinic in Minneapolis, MN, between October 2023 and November 2024. Testing was performed using 100% sunflower oil (La Tourangelle, Woodland, CA) in Finn Chambers (SmartPractice, Phoenix, AZ) applied to the upper back or thighs for 48 h. Readings were conducted on Day 2 and Day 4 or 7 using ICDRG criteria. The NACDG 2021–2022 standard series was tested concurrently, which included nickel sulfate 2.5% and 5% (pet.), Compositae mix 6% (pet.) and sesquiterpene lactone mix 0.1% (pet.) (Chemotechnique Diagnostics, Vellinge, Sweden). Zero reactions to sunflower oil were observed (0/568; 0%). In contrast, 122 patients (21.5%) reacted to nickel and 36 (6.3%) to Compositae-related allergens. No patients reacted to sunflower oil, including those positive to nickel or Compositae. Despite its widespread use, sunflower oil has rarely been studied as a potential allergen. Our data show no contact sensitization in over 500 patients, including those allergic to nickel or Compositae, suggesting it is not a clinically relevant allergen. Though sunflower is a member of the Compositae family, allergenic sesquiterpene lactones are typically confined to secretory plant structures like trichomes, found on leaves and flowers—not seeds [1, 2]. Solvent extracts of seeds may show trace allergen presence, but oil pressed from dehulled seeds contains only minute quantities [3, 4]. Additionally, sunflower seeds rank high among nickel-containing foods, which may prompt concern for nickel-allergic patients [5]. However, refined sunflower oil contains undetectable nickel levels even when derived from plants irrigated with nickel-contaminated water [6, 7]. Refining removes metal residues to improve stability and product quality [8]. Only one case report has implicated sunflower oil in contact allergy, and the case involved a lip balm with multiple consituents [9]. Our findings support its overall safety for topical use, even among populations sensitive to related allergens. This study is limited by its single-centre design and use of only one commercially available sunflower oil. Broader testing across formulations would further support these findings. Sarah Karels: conceptualization, investigation, writing – original draft, methodology, formal analysis, data curation. Sara Hylwa: data curation. Solvieg Ophaug: data curation. Katherine Lee: data curation. Anne Neeley: writing – review and editing, validation, supervision, data curation. Sara Hylwa is a paid speaker for the Contact Dermatitis Institute. This study was determined to be exempt from review by the HealthPartners Institute IRB. The authors declare no conflicts of interest.

  PublisherOA PDFDOI

• Contact Allergy to Clotrimazole in a Patient With Stasis Dermatitis

  Dermatitis · 2025-09-24

  articleOpen accessSenior authorCorresponding
  PublisherDOI

• Bullous pemphigoid in a patient with immunoglobulin A nephropathy

  Dermatology Online Journal · 2025-09-08

  articleOpen accessSenior author

  Bullous pemphigoid is a chronic autoimmune blistering disease typically presenting as non-specific pruritis following by the development of vesicles and bullae. A variety of medications and comorbid medical conditions have been associated with bullous pemphigoid. Herein, we present a case describing a potential novel association between immunoglobulin A nephropathy and bullous pemphigoid.

  PublisherOA PDFDOI

• High discrepancy rates in online allergen platforms: Implications for allergen avoidance

  Journal of the American Academy of Dermatology · 2025-12-23

  articleSenior author
  PublisherDOI

• <i>Letter:</i> Dermatologists Versus Skinfluencers on TikTok: Investigating the Categories, Allergenicity, and Cost of Recommended Skincare Products

  Dermatitis · 2025-09-12

  letterSenior author
  PublisherDOI

• Updates in Allergic Contact Dermatitis for the Inpatient Dermatologist

  Current Dermatology Reports · 2025-01-31

  articleSenior authorCorresponding
  PublisherDOI

• A Review of Academic Dermatologist Research Productivity Including Career Age Adjustments and Institutional Comparisons

  Archives of Dermatological Research · 2025-08-27

  review
  PublisherDOI

• <i>Letter:</i> No Wrinkles, No Worries? Evaluating Anti-Wrinkle Laundry Products for Formaldehyde Release Using the Chromotropic Acid Method

  Dermatitis · 2025-09-12

  letterSenior author
  PublisherDOI

• Contact Urticaria Testing at a Specialized Contact Dermatitis Clinic: Our Experience Over 5 Years

  Dermatitis · 2025-06-10 · 1 citations

  articleCorresponding

  Abstract: Background: Distinguishing between contact urticaria and allergic contact dermatitis can be challenging, and some patients may exhibit a combination of immediate and delayed-type reactions. Patients with suspected contact allergy are often referred to specialized patch testing centers, some of which may not offer contact urticaria testing. Objective: To examine the role of contact urticaria testing at our institution, specifically analyzing its ability to unveil reactions not detected during standard patch testing. Methods: Retrospective study of 2,396 patients comprehensively patch tested over a 5-year period. For each allergen in our contact urticaria series, positive reactions were assessed for concordant reactions on standard patch testing. A separate analysis including cross-reactors was conducted for fragrance and benzoate allergens. Results: Of 31 patients who received both contact urticaria and standard patch testing, 24 exhibited at least 1 positive contact urticaria reaction, amounting to 73 total reactions. 86% (63/73) of these reactions were identified with contact urticaria testing only. Conclusions: In our experience, contact urticaria testing revealed reactions not demonstrated during standard patch testing. Standardized contact urticaria testing protocols may result in improved diagnosis and disease clearance. Thus, patch testing centers might consider performing contact urticaria testing for patients with immediate-onset symptoms.

  PublisherDOI

Frequent coauthors

• Erin M. Warshaw

  114 shared

• Jamie P. Schlarbaum

  Oregon Health & Science University

  93 shared

• Anne B. Neeley

  Park Nicollet Clinic

  77 shared

• Cory A. Dunnick

  71 shared

• Andrew Scheman

  Northwestern University

  68 shared

• Zeke J. McKinney

  University of Minnesota

  64 shared

• D. Powell

  University of Utah

  64 shared

• Rosemary deShazo

  University of Utah

  64 shared