Matthew Zirwas, MD, is Founder of Bexley Dermatology Research Clinic in Bexley, Ohio.
“I think of hand eczema primarily in etiologic terms. My main thought is, what is actually driving the hand eczema? And really there are three options. Option number one is that it’s irritant contact dermatitis. Option number two is that it’s allergic contact dermatitis. And option number three is that it’s atopic dermatitis of the hands,” said Matthew Zirwas, MD, who presented “Pearls for Treating Hand Eczema” at the Diversity in Dermatology 2022 Conference.
“…most of the things that we used to think of as just ‘endogenous’ hand eczema, we now think of as really being atopic dermatitis of the hands, even in a patient who has no history of childhood rashes and in a patient with no personal or family history of atopy.”
Other diagnoses can also affect the hands, including lichen planus, discoid lupus, and psoriasis of the palms, said Dr. Zirwas.
“Those are things that you mainly differentiate based on biopsy, but you certainly can have a spongiotic component, especially with psoriasis of the palms and that gets to be really difficult.”
Distinguishing Types of Dermatitis
Distinguishing between psoriasiform atopic dermatitis of the palms and eczematous psoriasis of the palms can be tricky, said Dr. Zirwas.
“…as somebody who’s an expert in coming up with the etiology of dermatitis, [I] frequently can’t distinguish dermatitis of the palms that has psoriatic epidermal hyperplasia versus psoriasis of the palms that has a spongiotic component.”
Pearl No.1
Because the biopsy always comes back as psoriasiform spongiotic dermatitis with scattered eosinophils, which could be either atopic or psoriatic, Dr. Zirwas said he performs a diagnostic trial based on level of itch.
“The itchier it is, the more likely I am to think it’s atopic dermatitis, in which case I’ll give them a targeted biologic for atopic dermatitis. If that works, it confirms my diagnosis. If it doesn’t work, then I’m going to switch them over to a targeted biologic for psoriasis.”
By comparison, if the patient presents with less itch and more fissuring and pain, he said he begins first with a targeted biologic for psoriasis and, if necessary, moves to a targeted biologic for atopic dermatitis.
“Nobody can tell reliably (especially not dermatopathogists)…. Fortunately, we now have drugs that allow us to kind of figure out which it is.”
Pearl No.2
According to Dr. Zirwas, there are fairly reliable clues for distinguishing among irritant dermatitis, allergic contact dermatitis, and atopic dermatitis.
“Whenever I’m dealing with just a spongiotic dermatitis of the hands, usually, if it’s primarily dorsal hand and more interdigital with sparing of the palm, that’s most likely to be irritant contact dermatitis. If it is just the palm with complete sparing of the back of the hand and the web spaces, that is most commonly going to be atopic dermatitis of the palms, what we used to call dyshidrosis and pompholyx. If it involves both the palm and the dorsal hand, then it’s most likely allergic contact dermatitis and that’s really by exclusion because irritant dermatitis rarely affects the palm, and atopic dermatitis of the hands relatively rarely affects the back of the hands. And so something that affects both the palm and the dorsal is most likely going to be allergic contact dermatitis from soaps, moisturizers, things like that.”
These indicators suggest but do not guarantee diagnoses, said Dr. Zirwas. Still, they are a good place to start.
Eczema Interventions
Pearl No.3
Tell patients with hand eczema to wash their hands in cold water, said Dr. Zirwas.
“The biggest intervention you can make in terms of hand washing is not what soap they’re using or even what frequency they’re washing their hands. It’s the temperature of the water. Good evidence came out of COVID-19 for something that we’ve always thought about whenever we’re talking to our dermatitis patients about showering. We tell them, ‘Don’t take hot showers’, but we never tell them, ‘Don’t wash your hands in hot water’.”
In a study published in late 2020,1 water temperature affected hand dermatitis more than cleanser used or frequency of washing.
“The reason is that hot water essentially melts your cutaneous lipids—your natural protective oils—[and] lets them be rinsed away. If the water is cold, it actually hardens those intracellular lipids, makes it harder for the soap to remove them.”
Pearl No.4
Hand sanitizer is less irritating than hand washing and less likely to cause hand dermatitis, said Dr. Zirwas.
“The reason that’s not widely understood is that if you already have a little bit of hand dermatitis and you try to use hand sanitizer, it burns like crazy. But if you don’t already have hand dermatitis, the hand sanitizer is much better than washing your hands. And that goes with CDC recommendations.”
The CDC recommends the use of alcohol-based hand sanitizers over soap and water. For a patient with hand dermatitis, there are alcohol-free benzalkonium chloride-based hand sanitizers that can be good options, said Dr. Zirwas.
Allergic Contact Dermatitis
Pearl No.5
For patients with allergic contact dermatitis of the hands, have them carry their own soap instead of using the fragranced, preservative-filled, antibiotic soaps in public dispensers, said Dr. Zirwas.
“People can carry their own small bar of soap in a little container, or we can give them a sample container of something like Cetaphil gentle hand cleanser or CeraVe gentle cleanser, and they can refill that with a low allergenicity soap for times whenever they do need to wash their hands.”
Treating the Palms
The palms are the most challenging area to treat, whether it’s allergic contact dermatitis, atopic dermatitis, or palmar psoriasis, because the epidermis is thicker and products do not effectively penetrate the skin, said Dr. Zirwas.
Pearl No.6
“We do have a really good answer to that. And it’s not urea… we have a much better keratolytic and it’s actually the only keratolytic that is truly a keratolytic. It’s thioglycolic acid.”
Thioglycolic acid is hair removal cream (think Nair or Magic Shave), said Dr. Zirwas.
“What I typically tell people to do is, leave it on for about a minute, then firmly wipe it off. Wash your hands and put on your topical prescription agent after that, typically a high potency topical steroid or topical JAK inhibitor.”
Pretreatment with the depilatory results in a 10- to 40-fold increase in product penetration, according to a 2008 study published in the Journal of Investigative Dermatology,2 said Dr. Zirwas, who noted that this is often works for patients who have failed clobetasol under occlusion overnight.
“You do the hair removal cream followed by the clobetasol or by topical ruxolitinib. You do that once a day for about a week. Then typically after a week, [patients] can change to doing the hair removal cream, followed by the prescription topical maybe once or twice a week, and it’s all that they need to do.”
The initial challenge for patients is withstanding the burning sensation from the depilatory, said Dr. Zirwas.
But “because high potency topical steroids and JAK inhibitors are so fast acting, the fissures actually will heal pretty quickly.”
References
- Alsaidan MS, Abuyassin AH, Alsaeed ZH, Alshmmari SH, Bindaaj TF, Alhababi AA. The Prevalence and Determinants of Hand and Face Dermatitis during COVID-19 Pandemic: A Population-Based Survey. Dermatol Res Pract. 2020 Dec 5;2020:6627472. doi: 10.1155/2020/6627472. PMID: 33376481; PMCID: PMC7726962.
- Lee JN, Jee SH, Chan CC, Lo W, Dong CY, Lin SJ. The effects of depilatory agents as penetration enhancers on human stratum corneum structures. J Invest Dermatol. 2008 Sep;128(9):2240-7. doi: 10.1038/jid.2008.82. Epub 2008 Apr 10. PMID: 18401425.