Dermatitis and other skin disorders

Overall scale of disease

Prevalence

Estimates of the prevalence of occupational illnesses in Great Britain - meaning the total number of people ill at any given time - may be derived from the Self-reported Work-related Illness (SWI) module of questions included annually in the national Labour Force Survey (LFS). Latest results estimated that in 2008/09, 16 000 people who worked in the last 12 months suffered had "skin problems" caused or made worse by work (with a 95% Confidence Interval: 10 000 to 23 000) - see Table SWIT3W12.

The LFS surveys rely on self diagnosis and responses given therefore depend on lay people’s perceptions of medical matters. In particular, the wording of the LFS survey questionnaire means that estimates for "skin problems" also depend on respondents recognising these as an occupational illness - rather than, for example, a condition or complaint. Furthermore, where respondents are suffering from more than one illness, prevalence estimates are based on the illness they regard as most severe. Both these factors may tend to lead to an underestimation of the prevalence of occupational skin disease by the LFS surveys.

Incidence

Two data sources provide information about annual incident cases (new cases occurring each year) of occupational skin disease in Great Britain: the Department for Work and Pensions (DWP) Industrial Injuries and Disablement Benefit (IIDB) scheme and The Health and Occupation Reporting (THOR) network. Both are subject to underreporting and therefore underestimate the overall incidence. However, the THOR scheme does provide useful insights about high risk occupations and particular causal agents for occupational skin disease. The LFS survey is designed to provide a more comprehensive estimate of the total annual incidence.  However, because of the limited number of sample cases reporting incident cases of skin problems the only year for which it has been possible to produce a sufficiently robust incidence estimate has been 2006/07.

In 2008, there were 2180 cases of occupational skin disease by dermatologists and occupational physicians reporting to the EPIDERM and OPRA schemes within the THOR network (Table THORS01). This gives an incidence rate of about 75 cases per million workers in 2008, based on estimates of the total numbers employed. However, in a recent analysis of THOR data for 2002-2005, the average annual incidence rate of work related skin disease was 91.3 per million (95% Confidence Interval: 81.8-101.1 per million) as reported by dermatologists (EPIDERM), and 316.6 per million (95% Confidence Interval: 251.8-381.3 per million) as reported by occupational physicians (OPRA)². The latter rate is higher since allowance was made for the fact that occupational physicians serve only about 12% of the workforce estimated by the LFS.

Of the skin disease cases reported within THOR in 2008, 1573 (72%) were contact dermatitis and 406 (19%) - most of the remainder - were skin cancers. The majority of the cases seen by both dermatologists occupational physicians were contact dermatitis (71% for EPIDERM and 76% for OPRA in 2008) while only EPIDERM tends to pick up cases of skin cancer (only 1 case was reported by OPRA during last five years.) This is largely due to the fact that occupational physicians see very few patients who are over the age of 65, while the reverse is true of dermatologists. Hence, skin cancers and other diseases of long latency are much less likely to be picked up by OPRA. A full description of the various occupational dermatoses reported to EPIDERM and OPRA is given in Table THORS01.

Reports to EPIDERM and OPRA include only those cases of skin disease that were serious enough to be seen by a dermatologist or occurred in workplaces where there is access to occupational physicians. Furthermore, many cases that failed to be diagnosed at all or where the link with work activity was not recognised will not be included. Thus, the true incidence of occupational skin disease is likely to be substantially higher than suggested by EPIDERM/OPRA - particularly for those conditions such as contact dermatitis where there may be substantial numbers of less serious cases.

Evidence from the LFS suggests the incidence rate of skin disease to be at least 2.5 times that estimated from THOR.  In 2006/07, the only year for which an LFS based incidence estimate for “skin problems” is available, it is estimated that between 6 000 and 16 000 individuals who worked in the last 12 months suffered a new “skin problem” which they believed to be work-related, a rate of between 210 and 550 cases per million (Table SWIT6W12). 

Estimated incidence rates for new diagnoses of skin conditions made by participating general practitioners in the new UK surveillance scheme (THOR GP) are considerably higher than those based on both EPIDERM and the LFS. Between 2006 and 2008 the incidence rate was 1540 per million workers (see Table THORGP01, THORGP02, THORGP03, THORGP04, THORGP05, THORGP06, THORGP07)

The coverage of the IIDB scheme is much more restricted than that of THOR and typically identifies only the most severe cases of dermatitis. In 2008, there were 105 cases assessed for disablement benefit (Table IIDB03).

Age and sex

Of the diagnoses of occupational dermatitis within the THOR scheme in 2008 slightly more were among women (56%) than men (44%), though vast majority of skin cancers (99%) were among men (Table THORS01). Contact dermatitis tends to occur at a young age - particularly amongst female workers, however, for skin cancer the majority of the cases occur in those aged over 65 years (Table THORS02).

The majority of cases (85 per cent) of occupational skin disease in 2006-08 occurred in England, with 8 per cent in Scotland and 7 per cent in Wales (Table THORS03). For contact dermatitis the proportion of cases in England was slightly lower (70%) but for skin cancer, somewhat higher (96%).

Other information from reports by GPs

The total number of diagnoses of work-related ill health recorded by partipating general practitioners in the new UK surveillance scheme (THOR GP) in 2008 was 1289, of which 137 (10.4%) were skin conditions. This compares with a total of 1560 diagnoses in 2006 (the first year of the scheme), of which 139 cases (8.9%) were skin conditions, and a total of 1460 diagnosed in 2007, of which 150 (10.3%) were skin conditions. Skin disease diagnoses were substantially less likely to be issued with a sickness notification and tended to be associated with much shorter periods of sickness absence than average for all diagnoses (see Table THORGP01, THORGP02, THORGP03, THORGP04, THORGP05, THORGP06, THORGP07).