Diagnostic Approaches to Contact Dermatitis Overlap with Atopic Disease, With Walter Liszewski, MD

A session was presented during the 2026 Maui Derm Hawaii conference session was presented titled ‘Contact Dermatitis Update 2026,’ with challenges related to the management of a range of contact dermatitis issues being highlighted.1

Walter Liszewski, MD, associate professor of dermatology and cancer epidemiology at Northwestern University’s Feinberg School of Medicine, presented this session on contact dermatitis updates. Liszewski spoke with HCPLive in a previous interview regarding takeaways from the talk.2 In this new segment, Liszewski was asked how he recommends clinicians refine their diagnostic approach when contact dermatitis overlaps with atopic or other inflammatory skin diseases.

“The thing that's challenging is that, for atopic dermatitis, there is no diagnostic test,” Liszewski explained. “But for allergic contact dermatitis, there is. So if you have a patient with moderate to severe eczema and it's not improving with topicals, those patients are candidates for patch testing.”

If clinicians do patch testing and there are no allergens, Liszewski explained, then one can be more certain of irritant dermatitis or exclusively atopic dermatitis. The reason this is important, Liszewski expressed, is many of the drugs used to treat atopic dermatitis, such as lebrikizumab or dupilumab, will not be effective for most forms of allergic contact dermatitis. In other words, Liszewski stressed the importance of a precise cause, for not all treatments will be effective for all forms of eczema.

Liszewski was asked if clinicians could only take away 1 or 2 practice-changing points from his session, what he would want them to remember.

“The first thing is, we always need more people to do patch testing, and I'm someone who specializes in advanced patch testing,” Liszewski said. “I have 500 allergens in my clinic. I routinely test patients for more than 100 allergens. And technically, yes, that is the ideal way it should be done. But that's not the only way that needs to be done.”

If a clinician can only do the American Contact Dermatitis Society (ACDS) Core Allergen Series, updated to 90 allergens.3 The series, he noted, is a comprehensive patch-testing panel used to identify substances causing allergic contact dermatitis. Even the T.R.U.E. TEST panel diagnostic approach, Liszewski said, can be helpful.

“We need more dermatologists who are willing and capable of doing patch testing, because it can be transformative for many of our patients with chronic eczematous dermatitis,” Liszewski said. “The second thing that I would emphasize is that you need to read labels. One thing that I encourage all of you to do is, the next time you're at the grocery store, you're at a pharmacy, and you're looking at shampoos or lotions, look at a bunch of them. Look at the ingredients. Are there new chemicals you haven't seen before?”

For more information about this topic and related topics, view Liszewski’s full interview posted above. For more from Maui Derm, view the latest conference coverage.

The quotes implemented in this video summary were edited for clarity.

References

1. Liszewski W. Contact Dermatitis Update 2026. Presented at: Maui Derm Hawaii 2026; January 25-29, 2026; Maui, Hawaii.

2. Liszewski W. Contact Dermatitis Updates for 2026, With Walter Liszewski, MD. HCPLive. February 4, 2026. Accessed February 5, 2026. https://www.hcplive.com/view/contact-dermatitis-updates-2026-walter-liszewski-md.

3. Schalock PC, Dunnick CA, American Contact Dermatitis Society Core Allergen Series Committee, et al. American Contact Dermatitis Society Core Allergen Series: 2020 Update. Dermatitis. 2020 Sep-Oct;31(5):279-282. doi: 10.1097/DER.0000000000000621. PMID: 32947457.