Hand-Eczema Patch Tests in 788 of 4,438 Shanghai Patients

November 11, 2026

Doctor’s Notes · Life in Motion · Evidence Review

Editorial disclosure: The featured image is an AI-created illustration of a fictional work or daily-life scene. It is not a patient, diagnosis, before-and-after image or Dr. Arsy #003 treatment result.

Reader question: Which allergen signals remained after correcting many Shanghai patch-test comparisons?

Study snapshot

Study element	Reported detail
Population	4,438 patients patch tested in Shanghai from 2018 through 2023, including 788 cases with hand eczema.
Design	Retrospective cohort analysis of clinical patch-test records.
Comparator	Hand-eczema cases versus patch-tested patients without hand eczema, with sex, age, atopy and occupation subgroup analyses.
Timepoint	2018-2023.
Key result	Patch-test positivity in the hand-eczema group was 82.23%. After false-discovery-rate correction, N-isopropyl-N-phenyl-4-phenylenediamine was more common in hand eczema; several other signals were significant only in multivariable analyses.
Funding/conflict context	The indexed abstract does not provide a funding or conflict statement. It does not evaluate #003.

What was actually measured?

Patch-test positivity in the hand-eczema group was 82.23%. After false-discovery-rate correction, N-isopropyl-N-phenyl-4-phenylenediamine was more common in hand eczema; several other signals were significant only in multivariable analyses.

The correction for multiple comparisons matters: nominal multivariable signals should not be presented as equally robust to the FDR-confirmed finding.

The denominator defines the scope. A patch-test clinic, selected case series, compensation registry, online questionnaire, workplace cohort and general-population survey answer different questions. A percentage from one cannot be silently transferred to the others.

What the result does not prove

Retrospective referral population, uneven occupational subgroups, patch-test selection and multiple testing mean the results do not estimate community prevalence.

Association, timing and biological plausibility can strengthen an occupational interpretation, but observational evidence cannot automatically establish individual causation. Referral patterns, reporting practices, task mix, protective equipment, nonwork exposures and access to care may all change an estimate.

A PubMed record is a bibliographic source. PubMed indexing is not NIH endorsement of the authors' conclusions, this interpretation or any product.

Exposure detail matters more than the job label

Workers with the same title can handle different materials for different durations. Useful documentation identifies the exact product or process, the route of contact, glove or PPE material, wetness, friction, heat, dust, splash potential, frequency and how symptoms change away from the task.

A symptom survey can identify a pattern, a clinical examination can refine the differential diagnosis, and patch testing can identify delayed sensitization. None of those steps alone proves that a workplace material caused an individual condition. Clinical relevance still requires a credible exposure and time course.

Questions worth recording

Which task, product, glove, tool, metal, resin, cleanser, food, plant, dust or surface came before symptoms?
Where did the change begin, and did it improve on days away or after a process or PPE change?
How often were hands wet, washed, disinfected, occluded, rubbed, heated or exposed to cold?
Were labels, ingredient information and safety-data sheets reviewed with occupational health?
Did the problem affect dexterity, sleep, pace, attendance, work quality or safety?

Prevention comes before cosmetic care

Substitution, closed systems, local exhaust, splash control, safer cleaning methods, training and correctly selected protective equipment address exposure at its source. Gloves are not automatically protective: material, fit, breakthrough time, sweating, reuse and rubber accelerators all matter.

Do not deliberately place workplace products on skin to test a theory. Persistent, recurrent or spreading symptoms, drainage, fever, breathing symptoms, severe pain, rapidly worsening redness or major loss of function warrant professional evaluation.

Primary research and guidance

Where Dr. Arsy #003 fits

Dr. Arsy #003 is a cosmetic moisturizer for hydration, moisture-barrier support and dry-skin comfort. This study did not test #003. Its findings do not show that #003 treats, cures or prevents eczema, relieves pain or itch, neutralizes workplace chemicals, is appropriate for every person, or provides pediatric or 24-hour efficacy.

Continue the evidence series

Evidence note: This educational article separates reported findings from interpretation. It is not a diagnosis, treatment recommendation or workplace-safety determination.

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