“Don’t Touch This”: Contact Dermatitis Insights and Updates from Matthew Zirwas, MD

At this year’s Society of Dermatology Physician Associates (SDPA) Fall Dermatology Conference in Las Vegas, Nevada, Matthew Zirwas, MD, shared some emerging allergens, potential diagnosis challenges, and exciting treatment advancements in the world of contact dermatitis. “Update on Contact Dermatitis: Don't Touch This” was one of 3 sessions Zirwas led at this year’s conference.

TRANSCRIPT:

Zirwas: I'm Dr Matthew Zirwas. I'm a board-certified dermatologist in Columbus, Ohio. I'm part of DOCS dermatology group. I did my residency at the University of Pittsburgh, and I've been specializing in eczema and associated disorders for the last 20 years.

Dermatology Times: What topics did you cover during your session on contact dermatitis at SDPA Fall 2024?

Zirwas: So at the contact dermatitis session this year, we went over some of the new allergens that are kind of out there and a big deal. So, the allergen of the year this year was sulfites, I hate to say it. Scraping the bottom of the barrel, not an interesting allergen of the year. It's in some foods. Never been that convinced that I've seen people who really got that much better by avoiding it in foods. Very rare for it to be in any kind of topical product. Another one that's new and interesting ispersulfates. So, persulfates are primarily used as shock treatment in hot tubs, and that is one of the questions you should be asking anytime you see somebody with a new onset widespread rash. "Do you have a hot tub? Do you get in the hot tub?" If they do and you're not patch testing persulfates, tell them to stay out of their hot tub for 2 months. If they get better, tell them to get back in. If they get itchy and rashy again, you have confirmed that they are allergic to persulfates, and they need to go to sulfate-free shock, which they can go to their pool and spa dealer and ask about that, just incidentally. Totally unrelated to things like sulfate-free shampoo. No overlap between the two. The next big thing in the world of contact dermatitis; dietary nickel. So, this is the most missed diagnosis in all of dermatology. We know that it's about 1 to 2% of patients who have this, so it's close to as common as psoriasis. But I want to know, how many people have you diagnosed with systemic reactions to dietary nickel compared to how many patients have you diagnosed with psoriasis? Probably not even close, because we all tend to miss this diagnosis. If you patch test somebody and they're allergic to nickel and they've got a widespread rash, this should be your go-to and there is now a really good resource out there. If you just Google, "the low nickel diet," there is a really good cookbook that is a fantastic resource for these patients. It can really make a big difference in their lives. Now, the last thing is something that's just an interesting overview idea in the world of contact dermatitis. So believe it or not, contact dermatitis, we have almost no outcome studies, right? So, what do I mean by an outcome study? I mean studies that show what percent of people, who have a relevant positive patch test, actually get better, right? So how many people? Is the positive patch test just a red herring? And how many people does it cure? Well, we got a little bit of data this year, and the data was not very good news. So, it turned out that it looked like only about 10% of people with a relevant positive patch test had their dermatitis clear completely. About 50% got somewhat better and then in about 50% of people, avoiding their allergen did absolutely no good for them. Now the thing that I want you to remember with those people who don't get better when they avoid their allergen or only get partially better, don't think of those people as having recalcitrant contact dermatitis. Because really, what they probably have is atopic dermatitis. So if someone gets patch tested and then doesn't get better, your assumption should be, "Hey, maybe this isn't contact dermatitis, maybe it's atopic dermatitis," and then you treat them for the atopic dermatitis and see if they get better.

Dermatology Times: As the year winds down, what was one of the most exciting aspects of dermatology to you?

Zirwas: The most exciting aspect of dermatology in the past year for me is an easy one, and it has nothing to do with anything else I've talked about today. It is the rise of the drug, oral roflumilast. If you are not using oral roflumilast on essentially a daily basis in your practice, you are behind the times. So oral roflumilast is an oral PDE-4 inhibitor. It costs $10 a month through some of the mail order pharmacies. So mechanistically, it is identical to Otezla. However, it is substantially more effective. One of the really good randomized, double-blind trials we have comparing it to methotrexate, showed that 50% of people got to passing 90 and about 70% of people got to passing 75. And this is with a drug that is non-immunosuppressive and requires no labs. It does cause GI upset in about 10% of patients. It does cause depression in about 1%, just like apremilast. But it's 10 bucks a month without insurance. So, it's a phenomenally good drug to use. Am I using it primarily in psoriasis and eczema? No, because I've got even better drugs for both of those. But where it's amazing? Number one, in psoriasis and eczema patients, when, for whatever reason, you can't get access to an FDA-approved therapy. But then the places where it's super good; lichen planus, lichen planopilaris, oral lichen planus, generalized granuloma annulare, even localized GA, cutaneous connective tissue diseases, pyoderma gangrenosum, and hidradenitis suppurativa. So, all of these inflammatory dermatoses, we now have a new agent that is super easy to use, is really cheap, and is broad spectrum, and it's especially good for a lot of things we haven't had good treatments for up till now.

[Transcript has been edited for clarity.]