Dr. Jonathan I. Silverberg
“Guidelines on trigger avoidance are written as if it’s easy to do,” Jonathan I. Silverberg, MD, PhD, MPH, said during the Revolutionizing Atopic Dermatitis virtual symposium. “It turns out that trigger avoidance is really complicated.”
He and his colleagues conducted a study of most common triggers for itch based on a prospective dermatology practice–based study of 587 adults with AD . About two-thirds (65%) reported one or more itch trigger in the past week and 36% had three or more itch triggers in the past week. The two most common triggers were stress (35%) and sweat (31%).
“To me, this is provocative, because this is not how I was trained in residency,” said Dr. Silverberg, director of clinical research in the division of dermatology at George Washington University, Washington. “I was trained that it’s all about excess showering, dry air, or cold temperature. Those are important, but the most common triggers are stress and sweat.”
AD triggers are also commonly linked to seasonality. “If you ask patients when their AD is worse, sometimes it’s winter,” he said. “Sometimes it’s spring. Sometimes it’s summer. It turns out that there is a distinct set of triggers that are associated with AD seasonality.” Wintertime worsening of disease is associated with cold temperature and weather change, he continued, while springtime worsening of disease is often linked to weather change and dry air. Common summertime triggers for flares include hot temperature, heat, sweat, weather change, sunlight, humid air, and dry air. “In the fall, the weather change again comes up as a trigger. Humid air does as well.”
In their prospective study, Dr. Silverberg and colleagues found that 90% of those who had at least three itch triggers reported 3 months or less of AD remission in the past year, “meaning that 90% are reporting persistent disease when they have multiple itch triggers,” he said. In addition, 78% reported two or more flares per year and 61% reported that AD is worse during certain seasons.
Potential mitigation strategies for stress include stress management, biofeedback, meditation, relaxation training, and mindfulness. “These don’t necessarily require expensive psychotherapy,” he said. Freely available iPhone apps can be incorporated into daily practice, such as Calm, Relax with Andrew Johnson, Nature Sounds Relax and Sleep, Breathe2Relax, and Headspace.
Many AD patients are sedentary and avoid vigorous physical activity owing to heat and sweat as triggers. Simple solutions include exercising in a cooler temperature environment, “not just using fans,” he said. “Take a quick shower right after working out and consider pre- and/or post treatment with topical medication.”
High temperature and sweating can be problematic at bedtime, he continued. Even if the indoor temperature is 70° F, that might jump to 85° F or 90° F under a thick blanket. “That heat can trigger itch and may cause sweating, which can trigger itch,” said Dr. Silverberg, who has AD and is director of patch testing at George Washington University. Potential solutions include using a lighter blanket, lowering the indoor temperature, and wearing breathable pajamas.
Dryness, another common AD trigger, can be secondary to a combination of low outdoor and/or indoor humidity. “Lower outdoor humidity is a particular problem in the wintertime, because cold air doesn’t hold moisture as well,” he said. “That’s why the air feels much dryer in the wintertime. There’s also a problem of indoor heating and cooling. Sometimes central air systems can lower humidity to the point where it’s bone dry.”
In an effort to determine the impact of specific climatic factors on the U.S. prevalence of AD, Dr. Silverberg and colleagues conducted a study using a merged analysis of the 2007 National Survey of Children’s Health from a representative sample of 91,642 children aged 0-17 years and 2006-2007 measurements from the National Climate Data Center and Weather Service. They found that childhood AD prevalence was increased in geographical areas that use more indoor heat and cooling and had lower outdoor humidity. “So, we see that there’s a direct correlate of this dryness issue that is leading to more AD throughout the U.S.,” he said.
Practical solutions to mitigate the effect of dry air on AD include opening windows to allow entry of moist air, “which can be particularly helpful in residences that are overheated,” he said. “I deal with this a lot in patients who live in dormitories. Use humidifiers to add moisture back into the air. Aim for 40%-50% indoor humidity to avoid mold and dust mites. It’s better to use demineralized water to reduce bacterial growth. This can be helpful for aeroallergies. Of note, there are really no well-done studies that have examined the efficacy of humidifiers in AD, but based on our anecdotal experience, this is a good way to go.”
Cold temperatures and trigger intense itch, even in the setting of high humidity. “For me personally, this is one of my most brutal triggers,” Dr. Silverberg said. “When I’m in a place with extremes of cold, I get a rapid onset of itch, a mix of itch and pain, particularly on the dorsal hands. For solutions, you can encourage patients to avoid extremely low temperatures, to bundle up, and to potentially use hand warmers or other heating devices.”
Clothing can be a trigger as well, especially tight-fitting clothes, hot and nonbreathable clothes, and large-diameter wool, which has been shown to induce itching and irritation. Mitigation strategies include wearing loose-fitting, lightweight, nonirritating fabric. “Traditional cotton and silk fabrics have mixed evidence in improving AD but are generally safe,” he said. “Ultra- or superfine merino wool has been shown to be nonpruritic. There is sparse evidence to support chemically treated/coated clothing for AD, but this may be an emerging area.”
Dr. Silverberg pointed out variability of cultural perspectives and preferences for bathing practices, including temperature, duration, frequency, optimal bathing products, and the use of loofahs and other scrubbing products. “This stems from different perceptions of what it means to be clean, and how dry our skin should feel after a shower,” he said. “Many clinicians and patients were taught that regular bathing is harmful in AD. It turns out that’s not true.”
In a recently published systematic review and meta-analysis of 13 studies, he and his colleagues examined efficacy outcomes of different bathing/showering regimens in AD. All 13 studies showed numerically reduced AD severity with any bathing regimen in at least one time point. Numerical decreases over time were observed for body surface area (BSA), Eczema Area and Severity Index (EASI), and/or SCORAD measures for daily and less than daily bathing, with or without application of emollients or topical corticosteroids. In random effects regression models, taking baths more than or less than seven times per week were not associated with significant differences of Cohen’s D scores for EASI, SCORAD, or BSA. “The take-home message here is, let your AD patients bathe,” Dr. Silverberg said. “Bathing is good. It can be channeled to help the eczema, but it has to be done the right way.”
Patients should be counseled to use nonirritating cleansers and shampoos, avoid excessively long baths/showers, avoid excessively hot baths/showers, avoid excessive rubbing or scrubbing of skin, and to apply emollients and/or topical corticosteroids immediately after the bath/shower.
PROMIS Itch-Triggers is a simple and feasible checklist to screen for the most common itch triggers in AD in clinical practice (patients are asked to check off which of the following have caused their itch in the previous 7 days: cold temperature, hot temperature, heat, sweat, tight clothing, fragrances, boredom, talking about itch, stress, weather change, sunlight, humid air, dry air). “It takes less than 1 minute to complete,” he said. “Additional testing with skin patch and/or prick testing may be warranted to identify allergenic triggers.”
Dr. Silverberg reported that he is a consultant to and/or an advisory board member for several pharmaceutical companies. He is also a speaker for Regeneron and Sanofi and has received a grant from Galderma.