Factors ranging from demographics to the COVID-19 pandemic are shifting the landscape of occupational dermatoses.
Donald V. Belsito, MD, drilled down on the medical and office management challenges of workplace-related dermatoses in his presentation at the American College of Allergy, Asthma & Immunology 2021 Annual Scientific Meeting, held November 4 to 8 in New Orleans, Louisiana, and virtually.1
Belsito, who is the Leonard C. Harber Professor of Dermatology at Columbia University Irving Medical Center in New York, New York, provided a 360-degree overview of current key issues regarding occupational dermatoses and recommendations for best practices to optimize the next wave of change.
Q: Which occupations have shown the highest increase in occupational dermatoses and why?
In my view, the medical community has seen the biggest uptick in skin allergy cases because of COVID-19. Some health care workers experienced reactions to the accelerators used in both latex and nonlatex gloves that qualified as personal protective equipment; others reacted to antioxidants and other materials used in the gloves. The types of masks required for those working in the medical community can lead to occlusions, sweat-related irritation, worsening of seborrheic dermatitis, and rosacea flares, among other conditions.
N[non-oil]95 masks can cause pressure changes around the face that can trigger or worsen skin disorders as well as put pressure on the voices of workers who have to talk through them all day. Certain textile dyes used in cloth masks can trigger allergic contact dermatitis, as can formaldehyde/formaldehyde releasers in some polypropylene masks. However, the impact of COVID-19 on the hands has been most significant.
Overwashing leads to dry, cracked hands and skin with open fissures that allow allergens to penetrate more easily. This doesn’t affect just workers in the medical field. Reports about the virus that indicated it could persist 24 hours on some surfaces meant some nonmedical workers were wearing gloves, in some cases, 12 hours a day. They also experienced problems related to dry and cracked skin from overwashing their hands.
Q: How is the profile of occupational dermatoses changing overall, and why types of cases can dermatologists and allergists expect to treat now?
As the United States becomes a less industrialized country and a more tech-oriented one, we’re seeing a lot of skin diseases go away. Twenty years ago, when I was working in Kansas, I saw a lot of machinists with contact dermatitis. The same was true for workers in the manufacturing industry, eg, airline and auto industries. Now I’m seeing more health care workers, janitorial staff, bakers, cooks, and wet workers in various fields, while continuing to see those in construction, and warehousing/transportation. It is hard to predict exactly which professions will face increasing problems with work-related dermatoses. Computer production may be one of them. Electronics requires a low-humidity environment, which can dry out skin and open it up to allergens.
Q: Are the types of allergens changing as well?
There are some new materials but the most common cutaneous occupational allergens are still plants, metals, rubber additives, biocides, iso-thiazolinones, p-tertiary butyl phenol formal-dehyde resin, epoxies, acrylates, isocyanates, aliphatic amines, antibiotics, and fragrances, as well as “one-off ” occupational-related materials such as glutaraldehyde in dentistry, cocamide monoethanolamine in cutting oils, and sodium cocoamphopropionate in disinfectant soaps used by fast food workers. In terms of photoallergic chemicals, the top allergens include bithionol, fentichlor, and sunscreens.
Q: What allergens might be easily missed?
Those allergens likely to be missed are ones that are yet to be “discovered”. For example, through extensive detective work, European collaborators identified isobornyl acrylate, which often does not cross-react with other acrylates, as an important allergen in continuous glucose monitoring systems and it was not labeled on the product. Labeling is a real issue in industry, where the material safety data sheets [MSDS] often cite an ingredient as proprietary and do not need to list ingredients present at less than 1% unless they are carcinogenic.
While there is some movement toward full disclosure coming from other industries, such as cleaning products, this is strictly voluntarily. While cosmetics, drugs, and food require full labeling, workplace materials, as noted, do not. But there are other exposures (household products, toys, medical equipment like the CGM monitors, etc) that do not. Our regulatory issues in the United States are mired in politics and other issues, such as trade secrets. When I was president of the American Contact Dermatology Society in 2000, we tried to get nickel regulated in consumer products with intimate skin contact, like they have in Europe, and we could not get it passed through Congress.
Q: Is testing technology keeping pace?
I don’t see patch testing being replaced anytime soon. There are some who believe that the lymphocyte transformation test is a replacement for patch testing. However, despite years of experience with this test, the variability within the same laboratory and among different laboratories is high. To date, this test has not been validated and is not approved by any regulatory authority in the world.
As for patch testing, the difficulty is in the interpretation of the reaction seen. The allergen is tested under occlusion, and since many are also irritants, differentiating a mild allergic from irritant reaction requires great skill. Dermoscopy may help. But, in the patch testing arena, it is in its infancy, and will take time to be validated. As we move forward with computer technology in medicine, we may have instruments available that help physicians decide if the patch test results are irritant or allergic. Interpreting patch tests is not like assessing a numerical laboratory result. It is science, but also an art that depends on the skill of an individual person. Another issue with patch testing is that many insurance companies are not willing to approve more than a limited number of allergens, which may lead to missed diagnoses of allergic contact dermatitis.
Q: What best practices for testing do you think dermatologists should be more aware of?
The specificity and sensitivity of testing are very important. You need a sense of how irritating the material is and at what level it becomes irritating. You can’t test above irritant level because you can’t read the patch test. A good example is nickel, which we test as nickel sulfate. At 5%, there were a lot of irritant reactions. At 2.5%, there is some irritation, but not like 5%. The number of people with suspected nickel allergies who showed reactions at 5% and 2.5% was similar but higher at 5%. If you suspect your patient has an allergy, eg, to nickel, but the test is negative to the standard patch testing dose, you might need to try a higher concentration, but then you need to manage the irritant issue. Patch testing is not a binary test; there are often shades of gray. You can get false positives because of cutaneous hyperirritability; you can get false negatives because the patient got sun exposure or took prednisone recently; both diminish immunoreactivity. False negatives can also occur if you did not test a high enough concentration of the allergen. There can be a lot of variability that needs to be considered. Even when we were doing confirmatory studies for the FDA, people would come up negative on one side and positive on the other, and these were patients with a confirmed allergy. Patch testing is not perfect, but it is the best tool we have.
Q: You said that 25% of people with occupational dermatoses have a poor prognosis. What pipeline drugs could improve their outcomes?
A variety of treatments on the horizon could show promise. The European Commission approved upadacitinib [Rinvoq; AbbVie] as the first oral Janus kinase [JAK] inhibitor to treat moderate to severe atopic dermatitis in patients 12 years and older. In the United States, the FDA has approved ruxolitinib [Opzelura; Incyte], a topical selective JAK1/JAK2 inhibitor, for the treatment of mild to moderate atopic dermatitis in nonimmunocompromised patients 12 years and older whose disease is not adequately controlled with topical prescription therapies or when those therapies are not advisable.
JAK inhibitors may change the way we look at the treatment of allergic contact derma- titis. Right now, we can get rapid control with prednisone or cyclosporine, but they are not a long-term solution. Physicians and patients will have to have a conversation about the black box warnings on the JAK inhibitors. They need to address the differences in the possible adverse effects in the oral drugs vs the topicals, since topicals have a lower absorption rate. Unfortunately, topical ruxolitinib carries the same black box warning as the oral JAK inhibitors, which will likely cause physicians and patients to be leery of using.
Belsito reported no relevant disclosures.
1. Belsito DV. How to workup and manage occupational dermatoses. Presented at: American College of Allergy, Asthma & Immunology 2021 Annual Scientific Meet- ing; November 4-8, 2021; New Orleans, LA, and virtual.