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Epidemiology of Skin Disease in Europe

Hywel Williams1, Åke Svensson2, Thomas Diepgen3, Luigi Naldi4, Pieter-Jan Coenraads5, Peter Elsner6 Jean-Jacques Grob7, Jan Nico Bouwes Bavinck8 on behalf of The European Dermato-Epidemiology Network (EDEN)


1 University of Nottingham, UK
2 University of Lund, Malmö, Sweden
3 University of Heidelberg, Germany
4 Centro Studi GISED, Ospedali Riuniti di Bergamo, Italy
5 University of Groningen, The Netherlands
6 University of Jena, Germany
7 University of Marseilles, France
8 University of Leiden, The Netherlands

1. Introduction

What is epidemiology?
Epidemiology refers to the study of the distribution and causes of diseases in human populations (Grob et al. 1997, Williams & Strachan 1997). Epidemiology as applied to dermatology is thus concerned with finding out more about issues such as how many people suffer from skin disease in a given community such as the European Community, and the different ways that such skin diseases affect people in terms of adverse quality of life and loss of employment. More importantly, by contrasting affected people against those without disease with respect to a range of plausible causes, epidemiology offers one of the simplest and most direct ways of evaluating the causes of skin diseases in populations. Knowledge of causes then opens up the possibility for prevention of skin and venereal disease – a potentially powerful and perhaps more appropriate way of approaching the problem of skin disease at a population level than investment into expensive drugs, which may often only modify established disease.

Clinical epidemiology and health services research is also concerned with evaluating the efficacy and cost-effectiveness of treatments for skin disease, whether these be new drugs, ultraviolet light devices, herbal remedies or different ways of organising dermatological services. Whereas most clinical research is involved in describing individual cases, epidemiology is concerned with studying individuals with a particular skin disease in relation to entire populations, so that effective health care strategies that benefit all can be developed.

This short report summarises some important epidemiological aspects of skin diseases in Europe, and ends by highlighting important future health service and population research issues.

2. EDEN and the opportunities for studying skin disease in Europe

Recent progress
Although progress into understanding the epidemiology of skin diseases within Europe has been slow in the past due to a preoccupation of research which is concerned about determining disease mechanisms at a cellular level, the last years has witnessed a modest but encouraging growth in epidemiological research into skin disease. This is due in part to organisations such as the European Dermato-Epidemiology Network (EDEN) - an independent non-profit organisation of volunteers whose aim is to promote the highest standards of education and research into the causes and distribution of skin diseases within Europe.

EDEN was founded in 1995 in order to stimulate co-operation and high standards of research in epidemiology as applied to dermatology. EDEN is organised through a pan-European steering committee. In addition to its own collaborative research projects, EDEN has been successful in running teaching courses and sharing expertise at all major European dermatological meetings, as well as organising its own Congress in collaboration with the International Dermato-Epidemiology Association (IDEA) every three years. EDEN has helped to facilitate networking of like-minded researchers , and has initiated its own collaborative research projects such as the EDEN psoriasis project - a methodological review of all clinical trials of psoriasis over the last 20 years (Naldi et al. 2003). The aim of such a detailed review is to provide guidance on appropriate future study designs and to encourage better standards of clinical trial reporting in journals. A similar review of trials of interventions for treatment of hand -eczema - a common occupational disease of major economic importance, has also been completed (van Coevorden et al. 2004). A further EDEN project has involved a detailed critical review of prevalence surveys of common skin diseases such as psoriasis throughout Europe (Radulescu et al. 2003)

The opportunities for studying skin disease in a changing Europe
In one sense, Europe provides a unique “natural experiment” of different ethnic groups, different geophysical conditions such as climate, sunlight and terrain, different socio-economic conditions and varying environmental factors such as industrial pollution and airborne allergens in which to explore the possible causes of skin diseases. The varying methods of dermatological health care delivery within the many countries of Europe also provide a unique opportunity to evaluate the appropriateness and effectiveness of such health care systems in the light of population-based epidemiological data and high quality evidence of efficacy.

3. How common is skin disease in Europe?

At least one quarter have a skin disease at any one time
To date, no comprehensive surveys of the prevalence of skin diseases as a whole have been conducted across Europe. Indeed, apart from specific diseases such as childhood eczema and melanoma skin cancer, none have been conducted in more than one country. Surveys in individual countries suggest that skin conditions as a whole represent a large and important problem (Johnson 1978, Rea et al. 1976, Dalgard et al 2003). Thus, one survey of adults in London suggested that 22.5% had a skin disease that could benefit from medical care, yet only 24% of such individuals with moderate to severe skin disease had made use of medical services in the last 6 months ( Rea et al. 1976). These surveys, along with a trend to increasing consultation rates for skin disease as a whole, suggest that there is a large hidden iceberg of unmet dermatological need within Europe. This iceberg of dermatological need is likely to surface over the next 20 years as consumers of health care become more aware of their rights, and because some common skin diseases such as skin cancer and venous leg ulcers are becoming more common due to an increasingly ageing population (Williams 1997). Frequent travel between countries and abroad, migrant people in search of work, and widening socio-economic divides are also factors that could contribute to increases in infectious skin and venereal diseases.
Some estimates of the occurrence of common skin diseases (excluding skin cancer) are given in table 1 .

Inflammatory skin disease
Surveys of specific skin diseases such as childhood eczema (atopic dermatitis) suggest that like asthma and hay fever, it is a major problem within Europe, affecting around 10% of children overall. Highest rates (around 20%) are observed in Scandinavia and UK and the lowest rates of around 5% are found in South-Eastern Europe. Reasons for this North-West/South-East gradient are as yet unclear. Irritant and allergic contact dermatitis are also a serious problem affecting around 10% of adults. Hand eczema represents one of the four commonest occupationally-related diseases, accounting for substantial lost earning potential in young otherwise healthy populations.
Various European population based studies have suggested that psoriasis - a disease that can have a profound affect on quality of life of individuals - affects around 2% of the population, with two peaks of onset in early adulthood and in later life. Acne (teenage spots) is so common as to be almost universal during teenage years, yet surveys have suggested that few affected individuals receive good medical advice regarding the most appropriate treatment that can prevent lifelong facial scarring.

Infectious skin diseases
These may account for the bulk of skin diseases presenting to primary care physicians. Infectious skin diseases may be bacterial e.g. impetigo or boils, viral e.g. herpes simplex or warts, or fungal e.g. athlete’s foot or ringworm. Ectoparasites also consume a large burden of health care resources (Downs et al. 1999), especially when treating epidemics of head lice in schoolchildren and scabies outbreaks in nursing homes.

Chronic venous insufficiency and leg ulcers
Chronic venous insufficiency is a major although generally underestimated health problem which affects approximately 15% of the adult population in the European countries, with 1% suffering from manifest venous leg ulcers (e.g. 1 million persons in Germany). Venous ulcers in their most severe form are a debilitating condition, especially in the elderly. At present, management in terms of available treatment facilities and secondary prevention is far from adequate. Dermatology is the main medical specialty to take care of people with chronic venous insufficiency in most parts of Europe.

Table 1: Estimates of the frequencies of common skin diseases (without skin cancer) according to a selection of recent publications.

Disease

Study population

Prevalence

Reference

Atopic dermatitis

Swedish birth cohort


Swedish school children (5-6 yrs.)



Italian schoolchildren (9 yrs.)

Danish school children (12-16 yrs.)

point prevalence at 2 years of age = 7 %


lifetime prevalence = 20.7%
point prevalences:
in Gotenborg = 8.5%,
in Kristianstad = 11.5%

lifetime prevalence = 15.2%
point prevalence = 5.8%

lifetime prevalence = 21.3%
1-year prevalence = 6.7%
point prevalence = 3.6%

Böhme et al. 2001

Broberg et al. 2000



Girolomoni et al. 2003

Mortz et al. 2001

Contact Sensitisation

German adults(Population-based, nested case-control study)

Danish school children (12-16 years)

Prevalence = 40%
(any contact sensitisation)


prevalence = 15%

Schäfer et al. 2001


Mortz et al. 2001

Hand eczema

Swedish adults (large questionnaire survey)

Swedish school-children (16-19 yrs.)

Danish schoolchildren aged 12-16 years

Prevalence = 8%(including mild cases)


point prevalence = 4%,
1-year prevalence = 10%

point prevalence = 3%,
1-year prevalence = 9%

Meding et al. 2001

Yngveson et al. 1998

Mortz et al. 2001

Occupational Contact Dermatitis (OCD)

Review of registered OCD in different European countries

incidence rate = 0.5 to 1.9 cases / 1000 full-time workers per year. (Underestimated by 10 to 50 times?)

Diepgen & Coenraads 1999

Rosacea

Swedish office employees

point prevalence = 10% (according to clinical examination)

Berg & Lidén 1989

Psoriasis

Summary of 18 population-based studies within Europe

point prevalence = 1.7%, cumulative incidence = 2.1%

Radulescu et al. 2003

Leg ulcers

Swedish population (older than 70 years)

prevalence = 12.6%(healed and non-healed chronic leg ulcers)

Marklund et al. 2000

Skin Cancer
Melanoma and nonmelanoma (basal and squamous cell carcinoma) skin cancer (NMSC) are now the most common type of cancer in White populations and the incidence of skin cancer has reached epidemic proportions (Diepgen & Mahler 2002). According to recent population-based studies from Australia the incidence rate is over 2% for basal cell carcinoma (BCC) in males, 1% for squamous cell carcinoma (SCC) and over 50 new cases of melanoma per 100,000. Many cancer registries probably underestimate the true incidence, especially of NMSC (see table 2). Milder forms of skin cancer such as rodent ulcer (basal cell carcinoma) and squamous cell cancer can be treated adequately by surgical removal. The capacity of many current health care systems to cope with such surgical demand is currently stretched to maximum in some European countries due to the rising epidemic of skin cancer evident in Europe's ageing population.

Table 2: Age-standardized rates of nonmelanoma skin cancer (NMSC) in whites per 100,000 population from Australia, United States and Europe (selected studies after 1990, according to Diepgen & Mahler 2002)

Country Year of report Basal Cell Carcinoma Squamous Cell Carcinoma
male female male female
Australia          
- Townsville 1998 2055 1195 1332 755
- Nambour 1996 2074 1579 1035 472
- Tasmania 1993 145 83 64 20
           
United States          
- different 1994 407 212 81 26
- New Hampshire 1991 159 87 32 8
- Rochester 1997 175 124 155 71
           
Europe          
- Wales, U.K. 2000 128 105 25 9
- Hull, U.K. 1994 116 103 29 21
- Scotland 1998 50 37 18 8
- Finland 1999 49 45 7 4
- The Netherlands 1991 46 32 11 3

Melanoma skin cancer is the most serious form of skin cancer, and its incidence has been rising steeply in the white population over the last 30 years (doubling of cases every 10-15 years), probably due in part to increased leisure exposure to the sun. Melanoma skin cancer is preventable at least to some degree, yet approaches to educate the public on the dangers of sunbathing have been variable, ranging from non-existent in some European countries to highly proactive educational campaigns aimed at primary prevention (preventing the development of skin cancer in the first place) and secondary prevention (catching established disease early) in others. Melanoma also has the advantage of being curable when recognised at an early stage, yet facilities for detecting such early cases vary widely within relatively short distances in Europe.

Rarer skin diseases
Whilst it is true that less than 10 skin disease groups probably account for 70% of dermatological consultations, at least 1000 skin diseases have been recognised (Williams 1997). It is quite easy therefore to forget the importance of rarer skin such as epidermolysis bullosa (a genetic form of mechanical blistering which can result in severe scarring and deformity), vitiligo (a patchy and disfiguring complete loss of pigment in the skin), and severe autoimmune blistering disorders such as pemphigus (resulting in large areas of eroded skin and increased morbidity) when referring to skin disease only from a public health perspective. The study of such rare skin diseases is an area which lends itself very well to a Europe-wide approach in order to have sufficient numbers of patients to conduct reliable studies e.g., the mapping of molecular defects underlying genetic skin diseases may greatly profit from such joint European enterprises.

4. How does skin disease affect people?

Disabilities due to loss of function
Public sympathy and charity for people with skin disease is limited. This is surprising considering skin disease is so common and that it can affect people in so many ways. Thus scleroderma, both systemic and localised, directly restrict mobility and functioning of the limbs, and leg ulcers produce chronic pain and limit the ability to walk. Some inflammatory skin diseases such as occupational hand dermatitis or hand psoriasis confer a direct disability by affecting the ability to use one's hands. Atopic eczema and scabies are intensely itchy disorders, leading to sleep loss for sufferers and their families and lack of concentration due to drowsiness the following day.

Mortalities
Chronic suffering rather than mortality is characteristic for most skin diseases. Nevertheless, there are exceptions e.g. once melanoma has spread beyond the regional lymph nodes or into the bloodstream, the outlook can be very poor. Melanoma kills a disproportionate number of young economically active people when compared with other cancers (melanoma comprises 1-2% of all cancer-related fatalities). Several other less common skin cancers such as Merkel cell tumours, malignant fibrous histiocytomas, mycosis fungoides, other lymphomas, angiosarcomas, and Kaposi´s sarcoma are similarly aggressive or particularly difficult to treat. A wide range of multisystem dermatological diseases are associated with reduced life expectancy: collagen vascular diseases, acquired blistering diseases, genetic diseases like xeroderma pigmentosum, epidermolysis bullosa and many others. Rare skin diseases such as blistering drug reactions can result in a person losing almost their entire skin - as in a severe burn. In the absence of a correctly functioning skin, temperature regulation, salt and water balance and defence against infections are grossly impaired. These types of skin conditions can carry be associated with a mortality of around 30%.

Profound psychological effects
In addition to physical symptoms, perhaps the most significant way in which skin disease affects people is the effect it has on that person's psychological well-being (Ryan 1991). Disfiguring skin disease on visible sites such as the face (eg acne) can result in loss of self-esteem, depression and poorer job prospects. Indeed, quality of life scores for people with skin disease are often worse than people with more traditional "medical" disorders such as angina and hypertension. The skin is therefore a sensitive and dynamic organ that has a crucial and frequently underestimated social function.

High economic costs
Although it is true that skin disease is rarely life threatening, it is the product of its moderate morbidity times its high prevalence that places skin disease among the top four chronic disease problems when entire communities are considered. Various studies have assessed the economic impact of specific skin diseases and these have shown that direct costs are as high as many other diseases, with much of that cost being borne by patients as well as the State. Small changes in the way this balance functions can have a profound effect on a country's health care budget because skin disease affects so many people (Williams 1997, Verboom et al. 2002).

Other costs such as unemployment and losing an economically viable sector of a country's workforce are also important when considered at a population level. Indirect costs e.g. the adverse effects on quality of life and the opportunity costs due to loss of time spent for daily topical therapy and skin care in many skin diseases also need to be considered in such economic evaluations.

5. What are the causes of skin diseases in Europe?

Ultraviolet light
Due to lack of investment into researching the epidemiology of skin diseases, knowledge of the factors that predispose or precipitate various skin diseases is still patchy and at an early stage. Much epidemiological work in dermatology has evaluated the role of excessive ultraviolet light exposure in the various form of skin cancer. Whilst excessive sun is an important risk factor for skin cancer, other factors such as being born with a fair skin, red hair, having lots of moles and a family history of skin cancer are also important.

Eczema and psoriasis
The causes of childhood eczema are still not fully known, but genetic predisposition along with various allergic (e.g. house dust mite) and non-allergic factors such as irritation from rough textiles and soap have been shown to be important. In some cases of dermatitis, the specific allergen is known and can be tested for e.g. nickel dermatitis or fragrance allergy. Once identified by patch testing, they can be avoided, so eliminating the problem.

Psoriasis is also partly genetically determined, although the exact mode of inheritance is still unclear. Various European studies have suggested that both smoking and excessive alcohol consumption as well as dietary factors may be important risk factors for contributing to disease expression. In addition, several environmental triggering factors, e.g. infections and some drugs, have been identified.

Occupationally-acquired skin disease
Occupational skin diseases may represent a major burden to some industries (Diepgen & Coenraads 1999). Those that involve high exposure to irritant oils, soaps and wet work such as metal workers in the motor industry, hairdressers and nurses seem to get the worst problems. Other occupations are associated with specific allergic reactions e.g. those handling epoxy resin or cement workers exposed to chromate. Such reactions may lead to lifelong sensitivity and permanent loss from the workforce.

Other chemicals such as dioxins or colour developers can lead to specific forms of skin disease such as a severe form of acne (chloracne) and another inflammatory skin diseases called lichen planus.

Don't forget simple infections and ectoparasites
In some European countries, infectious skin diseases such as head lice, scabies, impetigo, infected bites, boils, cellulitis, fungal infections and venereal diseases such as gonorrhoea, syphilis and non-specific urethritis still abound even though effective treatments are readily available.

6. How can skin diseases be prevented in Europe?

Prevention of skin disease is still at a very early stage, even though the knowledge to formulate some preventative strategies is already available. Thus, measures aimed at changing the public's behaviour to avoid excessive sun exposure and to recognise the visible signs of melanoma and seeking advice at an early stage (especially those at high risk of disease) may have already had a substantial impact on reducing the mortality of this devastating disease. Other studies in Europe have suggested that at least one third of children born to parents with allergic disease can be prevented from developing atopic eczema through a range of measures aimed at reducing allergic factors before or around birth (Mar and Marks, 2000). Better labelling of cosmetic ingredients and working substances, along with legislation to reduce harmful exposures, may play an important part in reducing contact dermatitis. In Denmark for instance, the introduction of legislation to reduce nickel contact with the skin might have contributed to reducing nickel dermatitis, which can affect up to 20% of young women. Infectious skin diseases, such as outbreaks of fungal infections of the scalp, or head lice, are all preventable to some degree.

7. How are skin diseases treated in Europe?

Variation in health services for people with skin diseases in Europe
Perhaps one of the most striking anomalies of skin treatment within Europe is the large variation in the provision of dermatological services. Thus in one country such as the UK, where the National Health Service relies on a comprehensive primary care system, patients normally consult with their community general practitioner and only the most severe or difficult cases are referred to a hospital-based dermatologist. In other countries such as France and Germany, access to private dermatologists is possible on the high street without referral from a primary care practitioner.

Some countries such as Romania and Germany make heavy use of inpatient services whereas other countries conduct most care in an outpatient or day treatment setting. The density of dermatologists also varies dramatically across Europe ranging from 1 per 150,000 of the population in the UK to 1 per 20,000 in Italy and France (Williams 1997). The duration and type of training in order to become a dermatologist also varies substantially, even between different EU countries. These differences are due to the considerable heterogeneity in the definition of dermatology as a specialty and the range of tasks carried out by dermatologists across Europe – an activity that is currently being surveyed by EDEN. In countries such as Germany, Holland and France, dermatologists may be responsible and competent for multisystem dermatological diseases, cancer chemotherapy, dermatosurgery, dermatopathology, allergology, venereal diseases, chronic venous insufficiency and decubitus ulcers, male infertility, as well as traditional dermatology, whereas in the UK, a dermatologist might have a narrower range of responsibilities.

The point of illustrating such variation is twofold. First, such heterogeneity probably reflects historical working patterns that have developed according to health care policies from previous governments. Each country swears by its own system, and to be fair, perhaps those systems currently in operation are the most appropriate for that particular country given that healthcare is complex. Until good health services research is commissioned into examining the relative efficacy, cost-effectiveness, acceptability and appropriateness of the various dermatological systems operating within Europe, the debate on the optimal dermatological health care system for each particular country will continue. Second, the variation of healthcare system provides a wonderful opportunity to compare the outcomes in many different health care systems, although such comparative observational data will need to be handled carefully in view of the differences in patient selection and information provided by services in different countries.

How good is the evidence that skin treatments work?
Although it might appear obvious to a layman that dermatologists only use treatments
which are based on high quality randomised controlled clinical trials, the truth is that many treatments in current use lack such a clear evidential basis (Williams et al. 2003). In the absence of such evidence, it is understandable that dermatologists rely heavily on anecdote and past experience, especially for rare skin diseases. This should not detract from the task of conducting high quality clinical trials where possible - perhaps on a pan-European basis.

Systematic reviews i.e. summaries of the evidence for the prevention and treatment of skin diseases that have been conducted in an explicit and systematic way, are conducted by volunteers contributing to the Cochrane Skin Group (www.nottingham.ac.uk/~muzd ), which is based in Europe. The evidence from systematic reviews on skin disease produced to date point to a lack of useful and high quality data. In many cases, the main trials have reflected the priorities of the pharmaceutical industry as opposed to the sorts of questions generated by consumers of services and their carers. EDEN has made a significant contribution to the Cochrane Skin Group, and three members of the steering committee serve as editors.

8. The future of research and service development

Stepping back from the traditional hospital perspective
Epidemiology is very much involved in stepping back and evaluating the whole picture of skin disease from a population perspective. What is clear from the brief glimpse into the epidemiology of skin disease in Europe given in this section is that i) skin disease is very common ii) some skin diseases such as skin cancer are becoming more common and iii) that future demand for skin services is likely to increase due to growing consumer awareness and society's attitudes to people with skin impairments (Williams 1997). It is evident that skin disease can profoundly affect the quality of life for a sufferer, and that the economic consequences of industrial skin disease can also be high. Research into the causes of skin disease using an epidemiological approach is still in its infancy, yet already there are some pointers that some skin diseases can be prevented to some degree.

Four major research priorities
There appear to be at least four major knowledge gaps in relation to the epidemiology of skin disease in Europe:

The first is the complete absence of any comparative prevalence surveys of skin disease in general involving more than one country. Even though skin diseases have the advantage of being easily visible, such population-based surveys are difficult and costly to conduct. They nevertheless provide an essential foundation of data on which to plan appropriate health services.

The second is to explore the evidence of effectiveness for the various health care systems that currently operate within Europe. Such an evaluation should begin with the users perspective in mind, rather than possible protectionist motives by dermatologists. Such studies could initially be observational studies based on routinely data collected within current systems, which could then progress to more elaborate controlled intervention studies.

The third priority is to invest in epidemiological research that seeks to find out the causes of skin diseases which could, in turn, lead to disease prevention.

The fourth is to develop more links between epidemiology and laboratory research so that laboratory research priorities are more guided by important clinical questions thrown up by epidemiological and clinical research. As an example, epidemiological research suggesting that there were at least two different types of psoriasis can then be taken into account when undertaking genetic and cellular studies.

Only when these types of questions are answered will it be possible to have any sensible debate about which is best method for dealing with the increasing consultation and costs of treating skin diseases in Europe.

9. References and useful websites

Berg M, Lidén S. An epidemiological study of rosacea. Acta Derm Venereol 1989;69:419-423

Böhme M, Svensson Å, Kull I, Nordvall L, Wahlgren C-F. Clinical features of atopic dermatitis at two years of age: A prospective, population-based case-control study. Acta Derm Venereol 2001;81:193-197

Broberg A, Svensson Å, Borres M, Berg R. Atopic dermatitis in 5-6-year-old Swedish children: cumulative incidence, point prevalence, and severity scoring. Allergy 2000;55:1025-1029.

Dalgard F, Svensson A, Holm JO, Sundby J. Self-reported skin complaints: validation of a questionnaire for population surveys. Br J Dermatol. 2003;149:794-800.

Diepgen TL, Coenraads PJ. The epidemiology of occupational contact dermatitis
Int Arch Occup Environ Health 1999; 72: 496-506

Diepgen TL, Mahler V. The epidemiology of skin cancer. Br J Dermatol 2002; 146 Suppl.61: 1-6.

Downs A, Harvey I, Kennedy C. The epidemiology of head lice and scabies in the UK. Epidemiol Infect 1999;122:471-477.

Girolomoni G, Abeni D, Masini C, Sera F, Ayala F, Belloni-Fortina A, Bonifazi E, Fabbri P, Gelmetti C, Monfrecola G, Peserico A, Seidenari S,Gianetti A. The epidemiology of atopic dermatitis in Italian Schoolchildren. Allergy 2003;58:420-425.

Grob JJ, Stern RS, MacKie RM, Weinstock MA (ed), Epidemiology and Prevention of Skin Diseases. Oxford, Blackwell Scientific Publications, 1997.

Johnson M-LT. Skin conditions and related need for medical care among persons aged 1-74 years, United States, 1971-74. Vital and Health Statistics: Series 11, No. 212. DHEW publication No. (PHS) 79-1660. National Center for Health Statistics 1978:1-72.

Mar A, Marks R. Prevention of atopic dermatitis. In: Williams HC (ed). Atopic Dermatitis – the epidemiology, causes and prevention of atopic eczema. Cambridge University Press, Cambridge, 2000.

Marklund B, Sülau T, Lindholm C. Prevalence of non-healed and healed chronic leg ulcers in an elderly rural population. Scand J Prim Health Care 2000;18:58-60.

Meding B, Lidén C, Berglind N. Self -diagnosed dermatitis in adults. Results from a population survey in Stockholm. Contact dermatitis 2001;45:341-345

Mortz C, Lauritsen J, Bindslev-Jensen C, Andersen K. Prevalence of atopic dermatitis, asthma, allergic rhinitis, and hand and contact dermatitis in adolescents. The Odense adolescence cohort study on atopic diseases and dermatitis. Br J Dermatol 2001;144:523-532.

Naldi L, Svensson A, Diepgen TL, Elsner P, Grob JJ, Coenraads PJ, Bouwes Bavinck JN, Williams H on behalf of The European Dermato-Epidemiology Network (EDEN). Randomized clinical trials for psoriasis1977 to 2000: the EDEN survey. J Invest Dermatol 2003;120:738-741

Radulescu M, Diepgen TL, Weisshaar E, Williams H. What makes a good prevalence survey. In: Williams HC, Bigby M, Diepgen TL, Herxheimer A, Naldi L, Rzany B (eds.) Evidence-based Dermatology. BMJ Books, London, 2003

Rea JN, Newhouse ML, Halil T. Skin disease in Lambeth: a community study of prevalence and use of medical care. Brit J Prev Soc Med 1976;30:107-14.

Ryan TJ. Disability in dermatology. Br J Hosp Med 1991;46:33-6.

Schäfer T,Böhler E,Ruhdorfer S,Weigl L,Wessner D,Filipiak B,Wichmann H,Ring
J. Epidemiology of contact allergy in adults. Allergy 2001;56:1192-1196.

van Coevorden AM, Coenraads PJ, Svensson A, Bouwes Bavinck JN, Diepgen TL, Naldi L, Elsner P, Williams HC. Overview of studies of treatments for hand eczema – the EDEN hand-eczema survey. Br J Dermatol (2004, in press)

Verboom P, Hakkaart-van Roijen L, Sturkenboom M, de Zeeuw R, Menke H, Rutten F. The cost of atopic dermatitis in the Netherlands: an international comparison. Br J Dermatol 2002; 147:716-724.

Williams HC. Dermatology. In: Health Care Needs Assessment, second series. Stevens A, Raftery J (eds). Oxford, Radcliffe Medical Press 1997.

Williams HC, Strachan DP (eds). The Challenge of Dermato-Epidemiology. Boca Raton, CRC Press Inc., 1997.

Williams HC, Bigby M, Diepgen TL, Herxheimer A, Naldi L, Rzany B (eds.) Evidence-based Dermatology. BMJ Books, London, 2003

Yngveson M, Svensson Å, Isacsson Å. Prevalence of self-reported hand dermatosis in upper secondary school pupils. Acta Derm Venereol 1998;78:371-374.


Websites

EUROPEAN DERMATO-EPIDEMIOLOGY NETWORK (EDEN):
http://orgs.dermis.net/eden

COCHRANE SKIN GROUP:
http://www.nottingham.ac.uk/~muzd

EVIDENCE-BASED DERMATOLOGY
www.evidbasedderm.com

and
www.ebderm.org