Occupational Triggers Fuel Half of CHE Cases, Spanish Study Finds

Occupational exposure was suspected in more than half of patients treated for chronic hand eczema (CHE) at a Spanish allergy clinic, and health care and laboratory workers accounted for the largest share of those cases.¹ Patch testing linked most cases to a handful of familiar culprits—preservatives, nickel, and rubber accelerants—underscoring how often a hand rash traces back to a specific, avoidable exposure.

Why Occupational Hand Eczema Is Easy to Miss

CHE is diagnosed when hand eczema persists for more than 3 months or recurs at least twice within a year, after ruling out look-alike conditions such as psoriasis, lichen planus, scabies, and dermatophyte infection. The condition affects roughly 10% of adults and adolescents and is the most common occupational skin disease in the general population. It is also multifactorial: allergic contact dermatitis (ACD), irritant contact dermatitis (ICD), atopic hand eczema, and protein contact dermatitis can all contribute, and mixed phenotypes are common, which complicates diagnosis.

That diagnostic complexity is part of why hand eczema so often goes unresolved. According to the American Academy of Dermatology, pinpointing the cause of a hand rash can take considerable trial and error, since triggers range from wet work and detergents to latex gloves and workplace solvents, and relief typically requires identifying and avoiding the specific culprit rather than simply moisturizing.²

A Retrospective Review at a Spanish Allergy Clinic

The retrospective, single-center study, published as a research letter, reviewed patients 18 years and older treated for CHE at the Allergy Department of Clínica Universidad de Navarra in Spain between January 2021 and December 2023.¹ All patients underwent patch testing using the Spanish GEIDAC series (the country's standard contact-allergen panel) plus additional allergens and personal products, and sensitizations were considered clinically relevant based on exposure history, timing, and lesion location.

Among the 76 patients included, the mean age was 39.4 years, and 69.7% were female. Atopy, defined as atopic dermatitis, allergic rhinitis, or asthma, was present in 36.8% of patients. Hyperkeratosis was the most common eczema phenotype (17.1%), followed by pulpitis (11.8%), and 22.4% of patients had more than 1 concurrent phenotype; however, most patients' eczema didn't fit a single defined phenotype. By etiology, ACD accounted for 57.9% of cases, ICD for 35.5%, and mixed contact dermatitis, dyshidrotic eczema, and atopic dermatitis for smaller shares.

Occupational Exposure and Patch Test Findings

Occupational exposure was suspected in 52.6% of patients, most often among health and laboratory workers (19.7%) and cleaning personnel (9.2%). The median latency between the start of workplace exposure and eczema onset was 32 months, and while it was numerically shorter in atopic patients (6.5 months) than nonatopic patients (65.5 months), the difference did not reach statistical significance (P = .0744).

Patch testing found that 61.8% of detected sensitizations were clinically relevant, most commonly to Kathon CG (14.9%), nickel (12.8%), thiuram mix (12.8%), and balsam of Peru (12.8%); nearly 30% of patients had more than 1 relevant sensitization. “Patch tests with standard allergen batteries are crucial, as the etiology of ACD can often be unexpected,” the authors wrote, noting that more than half of patients had already consulted another center before reaching an accurate diagnosis.

Disease Burden, Outcomes, and Limitations

The occupational toll was measurable, if modest by comparison: 4.0% of patients required medical leave, and 2.6% needed a workstation change, well below the roughly 28% sick-leave rate that prior European CHE cohorts have reported, the authors noted. Patients with eczema involving 3 body locations were significantly more likely to require a workstation change (P < .001). After treatment and allergen-avoidance counseling, 63.0% of patients achieved full improvement, 29.6% had partial improvement, and just 7.4% saw recurrence or no improvement at all.

The authors acknowledged that their heterogeneous patient population, drawn partly from mutual insurance company referrals, may have inflated the apparent prevalence of occupational CHE and, as findings from an allergy reference center, of atopy as well. The Hand Eczema Severity Index was also not measured in all patients, limiting how precisely disease severity could be tracked alongside outcomes.

For clinicians, the findings reinforce that a comprehensive allergy work-up, not just a topical prescription, is often what stands between a patient and lasting relief. Earlier referral for patch testing, the authors suggested, could prevent some of the sensitizations and lost workdays that come with a diagnosis delayed.

References

1. Sánchez-Fernández S, Carvallo A, Aguado L, Gastaminza G, D'Amelio CM. Hands at risk: decoding clinical profiles and occupational causes in chronic hand eczema. Allergol Int. 2026;75:504-505. doi:10.1016/j.alit.2026.03.002
2. American Academy of Dermatology. Dry, scaly, and painful hands could be hand eczema. Accessed August 7, 2026. https://www.aad.org/public/diseases/eczema/types/hand-eczema