More About Eczema

What’s already known about this topic?
• Occupational hand eczema may be persistent even if the
previous exposure does not continue, but the prognostic
factors for the continuation are not clear. Long-term
prognosis has been analysed in only a few studies.
• Change of occupation has, in some studies, but not in
all, led to better prognosis.
What does this study add?
• In this study, sample size and response rate were high,
and the study population included all occupations.
• The strongest risk factor for the continuation of occupational
hand eczema was a long duration of eczema
before diagnosis, which emphasizes the importance of
early diagnosis and interventions.
• Contact allergies did not impair the healing.
• Medical and economic prognosis was better among
patients who had changed their occupation.

Healing of hand eczema

Healing of hand eczema

The healing of OHE 7–14 years after the diagnosis, defined
as absence of eczema during the last 12 months, is presented
in Table 2. As many as 40% of the patients had no hand
eczema during the past 12 months. The healing of OHE was
poorer in patients with skin or respiratory atopy compared
with those with no atopy. The duration of hand eczema
before the diagnosis correlated most significantly with healing:
it was most frequent among patients whose hand
eczema had lasted a year or less. The presence of workrelated
chromate allergy was associated with poor healing. In
the multivariate logistic regression analysis, change of occupation,
duration of hand eczema before diagnosis, and skin
and respiratory atopy were significant risk factors for the
continuation of OHE (Table 3).
Table 2 Healing of occupational hand eczema (not present during the
last 12 months) at 7–14 years after diagnosis (n = 605)
OHE healed, n (%)
Sex
Men (n = 275) 105 (38)
Women (n = 330) 135 (41)
Agea
< 45 years (n = 320) 128 (40)
‡ 45 years (n = 285) 112 (39)
Atopy
No atopy (n = 440) 192 (44)
Skin atopy (n = 93) 29 (31)
Respiratory atopyb (n = 72) 19 (26)
P = 0Æ004
Patch test results
Negative patch tests (n = 128) 41 (32)
Nickel allergyc (n = 146) 60 (41)
Any other contact allergy (n = 331) 139 (42)
Duration of OHEd
0–1 year (n = 184) 103 (56)
1–2 years (n = 109) 33 (30)
2–5 years (n = 127) 50 (39)
5–10 years (n = 86) 29 (34)
Over 10 years (n = 85) 18 (21)
P < 0Æ0001
Occupationa
Dental personnel (n = 55) 24 (44)
Food-related occupation (n = 52) 16 (31)
Machinery mechanics (n = 42) 19 (45)
Farmers (n = 34) 15 (44)
Hairdressers (n = 32) 13 (41)
Machinists (n = 29) 10 (34)
Health care workers (n = 25) 9 (36)
Other (n = 336) 134 (40)
Diagnosis
ACD (n = 354) 151 (43)
ICD (n = 251) 89 (35)
Work-related allergy
Rubber chemicals (n = 49) 15 (31)
Formaldehyde (n = 38) 12 (32)
Epoxy chemicals (n = 36) 21 (58)
Acrylates (n = 31) 20 (65)
Chromate (n = 15) 2 (13)
Other (n = 436) 170 (39)
P = 0Æ001
All (n = 605) 240 (40)
aAt time of diagnosis. bOnly respiratory atopy without skin
atopy. cMay include other contact allergies. dFrom onset of
symptoms to diagnosis. OHE, occupational hand eczema; ACD,
allergic contact dermatitis; ICD, irritant contact dermatitis.
P-values are shown only when P < 0Æ05.
Table 3 Odds ratios (ORs) with 95% confidence intervals (CIs) for
continuation of occupational hand eczema (OHE) at 7–14 years after
diagnosis (n = 605)
OR (95% CI)
Agea
< 45 years 1
‡ 45 years 0Æ80 (0Æ53–1Æ21)
Sex
Women 1
Men 1Æ30 (0Æ83–2Æ04)
Atopy
No atopy 1
Skin atopy 1Æ86 (1Æ08–3Æ19)
Respiratory atopyb 2Æ69 (1Æ44–4Æ92)
Patch test results
Negative patch tests 1
Nickel allergyc 0Æ74 (0Æ39–1Æ40)
Any other contact allergy 0Æ67 (0Æ39–1Æ18)
Duration of OHEd
0–1 year 1
1–2 years 3Æ05 (1Æ78–5Æ21)
2–5 years 1Æ90 (1Æ16–3Æ09)
5–10 years 2Æ57 (1Æ44–4Æ58)
Over 10 years 4Æ55 (2Æ38–8Æ71)
Occupationa
Other than below 1
Dental personnel 1Æ13 (0Æ55–2Æ32)
Food-related occupation 1Æ86 (0Æ91–3Æ80)
Machinery mechanics 0Æ72 (0Æ35–1Æ49)
Farmers 0Æ78 (0Æ36–1Æ67)
Hairdressers 0Æ91 (0Æ39–2Æ10)
Machinists 1Æ27 (0Æ53–3Æ03)
Health care workers 1Æ07 (0Æ40–2Æ86)
Change of occupation
Yes 1
No 1Æ55 (1Æ03–2Æ34)
Work-related contact allergy
No work-related contact allergy 1
Rubber chemicals 1Æ58 (0Æ75–3Æ33)
Formaldehyde 1Æ08 (0Æ47–2Æ46)
Epoxy chemicals 0Æ58 (0Æ25–1Æ37)
Acrylates 0Æ50 (0Æ19–1Æ29)
Chromate 2Æ83 (0Æ58–13Æ78)
Other than above 0Æ85 (0Æ53–1Æ38)
aAt time of diagnosis. bOnly respiratory atopy without skin
atopy. cMay include other contact allergies. dFrom onset of
symptoms to diagnosis. Statistically significant results are shown
in bold.

Classification of diagnoses and atopy

Classification of diagnoses and atopy
Data on diagnosis, occupation, skin and respiratory atopy, and
contact allergies were collected from the patient files.
The diagnoses were based on a clinical examination by a
dermatologist and patch and skin prick test results. All patients
were tested with extensive patch tests including occupationspecific
test series and with patients’ work-related chemicals
and materials.
OHE was categorized as occupational allergic contact dermatitis
(ACD) or irritant contact dermatitis (ICD). The definition
of ACD included a work-related contact allergy confirmed in
patch tests and relevant occupational skin exposure and hand
eczema. ICD was defined by the following criteria: exposure
to irritants at work, the clinical picture of the hand eczema
correlating with the exposure at work, the eczema clearing up
when not working, and the absence of relevant work-related
contact allergies. Only one main diagnosis (either ACD or
ICD) per patient was analysed.
Skin atopy was defined as either present or past atopic
dermatitis. If the patient had no skin atopy, but had a history of
hay fever or atopic respiratory disease and ⁄or positive skin prick
tests to common environmental allergens, the classification of
respiratory atopy was applied. Data on occupational ACD from
chromium compounds, rubber chemicals, epoxy chemicals, acrylates
and formaldehyde were analysed separately.
The duration of the eczema was calculated from the onset
of symptoms to the time of diagnosis.

Longterm Eczema

Background Long-term follow-up studies on the prognosis and consequences of
occupational hand eczema (OHE) and the prognostic risk factors for persistent
OHE are sparse.
Objectives To determine the medical and occupational outcome after a follow-up of
7–14 years in 605 patients diagnosed with OHE and to identify the prognostic
risk factors for the continuation of hand eczema.
Methods Patients examined at the Finnish Institute of Occupational Health in
1994–2001 completed a follow-up questionnaire 7–14 years after diagnosis.
Results The hand eczema had healed (no eczema during the last year) in 40% of
patients with OHE. The duration of hand eczema before diagnosis was strongly associated
with the continuation of eczema. Age, sex and diagnosis (allergic or irritant
contact dermatitis) were not associated with the prognosis, but skin atopy, and
especially respiratory atopy, were correlated with the continuation of hand eczema.
Contact allergies in general were not risk factors for persistent OHE, but the presence
of a work-related chromate allergy was associated with poor healing. A total
of 34% of patients had changed their occupation due to OHE, and their long-term
prognosis was better than those who had not. The hand eczema of patients originally
in food-related occupations continued on an unfavourable course.
Conclusions In the logistic model, risk factors for the continuation of OHE were a
long duration of hand eczema before diagnosis, respiratory atopy, skin atopy,
and continuation in the same occupation. Those who ended up changing
occupation due to their OHE had a better medical and economic prognosis.
Hand eczema is often a chronic condition. In follow-up studies
of nonoccupational hand eczema (non-OHE), healing rates
have ranged between 18% and 41%.1–6 In studies with varying
follow-up periods, occupational hand eczema (OHE) has
been reported to heal in 21–72% of all cases.7–20 Only a few
long-term follow-up studies have been published previously,
7,10,15,18–20 and the prognosis in these has not always been
better than that in short-term studies. In some studies, a
change of job or occupation has not led to improvement of
occupational skin disease.8–10,21 The most frequently reported
predictive factors for poor prognosis (continuation of the
OHE in the absence of further exposure) include
atopy,7,12,15,22 contact allergies,7,8,12,23 older age,21,24,25 and
the severity21,26 and duration26 of the eczema.
In our previous study, the occupational skin disease had
healed in 27% of the patients 6 months after diagnosis.27 To
determine the long-term prognosis of OHE, we sent a questionnaire
to the patients diagnosed with OHE at the Finnish
Institute of Occupational Health (FIOH) 7–14 years previously
who had answered the earlier questionnaire.
Materials and methods
Study population and design
FIOH is a national referral unit to which patients are referred
by insurance companies, occupational physicians and dermatologists.
Patients who were diagnosed with an occupational
skin disease during the period 1994–2001 at FIOH and who
had answered a follow-up questionnaire 6 months after their
diagnosis were sent a new questionnaire in 2008. In total,
605 patients who returned the completed questionnaire and
who had OHE in the fingers, palms, dorsa of the hands, wrists
or forearms were included in this study. The response rate
was 80Æ1% (605 of 755).