Structured Workup Allows for Clearer Diagnoses for Patients With CHE

A dedicated case report form used across 10 Italian dermatology clinics enabled etiological classification in more than 80% of people with chronic hand eczema, highlighting the value of structured diagnostic approaches in a condition long challenged by clinical heterogeneity.¹

The Case for Getting Diagnosis Right in Chronic Hand Eczema

Chronic hand eczema (CHE) is defined as eczema of the hands and wrists that persists for more than 3 months or recurs at least twice within a 12-month period. The condition affects a broad population, carries significant quality of life (QOL) consequences, and often proves resistant to standard therapies. Its multifactorial pathogenesis—spanning irritant exposure, contact allergens, and atopic background—makes both classification and treatment selection difficult in real-world settings.

Several classification systems have been proposed, but none is universally accepted. As newer targeted therapies, including the topical pan-Janus kinase inhibitor delgocitinib cream, approved by the European Medicines Agency in September 2024 for moderate to severe CHE, and investigational biologics, become available, accurate subtyping of patients has taken on greater clinical urgency.

The Italian Society of Allergological, Occupational and Environmental Dermatology (SIDAPA) designed this multicenter study to test whether a structured case report form (CRF) could support consistent, comprehensive workup and etiological classification of people with CHE across diverse clinical settings.

A 2025 narrative review published in Acta Dermato-Venereologica reinforced the scope of this unmet need, noting that while CHE carries notable physical, psychosocial, occupational, and socioeconomic burdens for patients, awareness of the disease and the patient experience remains poor among clinicians.² The review highlighted that improved understanding of CHE's underlying pathogenesis and clinical subtypes is essential to empower health care providers to diagnose the condition more quickly and accurately, and to offer appropriate holistic care—goals that align directly with the intent of the SIDAPA CRF initiative.¹

Who Was Studied and What Was Measured

The cross-sectional study enrolled 207 adult patients with CHE across 10 Italian patch test clinics from January 2024 to May 2025. People with co-occurring inflammatory or infectious hand conditions, such as psoriasis or mycoses, were excluded. The mean (SD) patient age was 41.1 (15.6) years, and 68.6% of participants were female. Females were younger on average than males (39.4 [5.0] vs 44.8 [16.2] years). The mean disease duration was 6.0 (8.1) years.

An atopic background was present in 66.7% of participants. More than half of all patients (57.0%) worked in occupations considered at risk for CHE, including wet work roles such as health care, food service, and hairdressing. Frequent or very frequent handwashing (more than 11 times per day) was reported by more than 60% of patients.

A Structured Form Unlocks Etiological Answers for Most Patients

Using the CRF, clinicians achieved a definitive etiological diagnosis in 82.6% of participants. Irritant contact dermatitis was the most common subtype, identified in 52.7% of patients, followed by allergic contact dermatitis in 24.2% and atopic dermatitis in 16.9%. Twenty-two patients (10.6%) had mixed etiologies, and the etiology remained unclear in 17.4%.

In contrast, morphological (clinical) subtype classification proved more difficult, with only 29.0% of patients meeting criteria for a recognized clinical subtype. Hyperkeratotic eczema (12.1%) and acute recurrent vesicular eczema (9.7%) were the most frequently identified morphological presentations. The authors noted that this difficulty suggests current guidelines may need revision with respect to clinical subtype classification.

Patch Testing Reveals Allergen Burden and Severity Links

All patients underwent patch testing per protocol. Nearly half (47.8%) had at least 1 positive reaction, though only 24.2% of all participants had reactions considered relevant to their CHE and were classified as having allergic contact dermatitis. Methylisothiazolinone, 2-hydroxyethylmetacrylate, and p-phenylenediamine were the most frequently identified relevant contact allergens. On multivariate analysis, relevant positive patch test reactions were significantly associated with the most severe CHE cases.

Disease severity was substantial across the cohort. CHE was rated moderate to severe in 58.9% of patients using the Hand Eczema Severity Index (HECSI) and in 56.0% using the Investigator's Global Assessment of CHE. Regarding treatment response, topical corticosteroids—used by 97.1% of patients at some point—frequently proved inadequate; 81.4% of those who had used high-potency topical corticosteroids reported partial, no, or adverse response. QOL impact was considerable, with 85.5% of patients scoring in the moderate to very severe range on the Quality of Life in Hand Eczema Questionnaire.

The authors acknowledged several limitations. Diagnosis of irritant contact dermatitis relied on patient-reported activity data rather than objective testing, introducing potential for misclassification. Some relevant contact allergies in allergic contact dermatitis cases may have gone undetected because integrative patch test series or repeat open application testing with patients' own products was not uniformly applied. The study population was relatively small and the observation period short, and the CRF was not designed to support detailed monitoring of responses to newer therapies.

The researchers concluded that structured diagnostic evaluation can meaningfully clarify etiology in most people with CHE. As they wrote in the study, "An accurate clinical workup can lead to CHE clinical and etiological classification in about 80% of patients and may facilitate tailored treatment strategies."

With novel treatments increasingly available, this kind of systematic characterization may prove essential to matching patients to the therapies most likely to benefit them.

References

1. Gallo R, Guarneri F, Hansel K, et al. Real-life workup of chronic hand eczema using a dedicated case report form: a SIDAPA multicentre study. Contact Dermatitis. 2026;94:662-676. doi:10.1111/cod.70105
2. Molin S, Guttman-Yassky E, Thyssen JP, Bewley A. Chronic hand eczema, real world, and patient centricity: a narrative review. Acta Dermato-Venereologica. 2025;105:adv42596. doi:10.2340/actadv.v105.42596