5.11.3. Data description and analysis

 

Diseases of the skin are particularly common and varied owing to the large size of the skin, its complex structure and its permanent exposure to environmental influences. The number of skin diseases has been estimated to be as high as 3000, not counting questionable or ill-defined subtypes; this figure is higher than for that for diseases of any other organ of the body. Every individual is affected by skin problems during lifetime. The prevalence of skin diseases tends to increase with age, and there is hardly any individual over 50 years of age who does not need dermatologic care (Williams et al, 2006).

 

Skin diseases are a major source of morbidity. For the population as a whole, morbidity results mainly from chronic dermatologic illness. Occupational dermatosis (eczema) range among the most frequent causes of occupational disability, need for job retraining, and even invalid status with accompanying social costs (Dalgard et al, 2003).

Relatively few skin diseases are directly and acutely life threatening; included in this small group are acute severe intolerance reactions such as anaphylaxis and angio-edema, bee and wasp venom allergy, drug rashes such as the carbamazepine hypersensitivity syndrome or toxic epidermal necrolysis.

Chronic severe skin disease accounts for the most part of the patient’s suffering and incapacitation: psoriasis, atopic dermatitis, recalcitrant bullous diseases, chronic wounds such as venous and decubitus ulcers, smouldering skin lymphomas (usually mycosis fungoides), scleroderma and geno-dermatosis including severe ichthyoses and hereditary bullous diseases. Some of the most aggressive tumours arise in the skin: melanoma, squamous cell carcinoma, some types of skin lymphomas, Merkel cell tumours and others (See Chapter 4.3).

Some skin diseases may not seem to qualify as severe diseases at first glance, but their psychological impact, particularly on the developing personality, may be very detrimental. Acne vulgaris, disfiguring birth marks or cutaneous anomalies have a high impact on wellness and the social abilities of adolescents, as does balding (androgenetic alopecia) for both sexes in adulthood. Psychological consequences of atopic dermatitis vexes its bearers not only by incessant itch, but also by its appearance, (“atopic psyche”). Dermatology has to satisfy the patients with those abundant common and relatively mild ailments which ill the waiting rooms and may not be so easy to diagnose and treat despite their often seemingly trivial background: viral warts, eczemas of various kinds, simple bacterial, viral and fungal skin infections, insect bites, dandruff (seborrheic eczema of the scalp), dry skin, the great stigma of ageing skin, venous insufficiency of the lower limbs, etc. Among all these, the skin specialist has always to keep in mind that skin symptoms may be a warning signal of life-threatening internal disease.

 

Prevalence of selected dermatological diseases are reported in Tables 5.11.1 and 5.11.2.

 

Table 5.11.1. Prevalence of selected dermatological diseases

 

DISEASE	STUDY POPULATION	PREVALENCE	AUTHORS
Atopic Dermatitis	Swedish birth cohort	Point prevalence at 2 yrs of age=7%	Böhme M, et al
	Swedish school children (5-6 yrs)	Lifetime prevalence=20.7%	Broberg A, et al
	Italian school children (9 yrs)	Lifetime prevalence=15.2% Point prevalence=5.8%	Girolomoni G, et al
	Danish school children (12-16 yrs)	Lifetime prevalence=21.3% 1-year prevalence=6.7% Point prevalence=3.6%	Mortz C, et al
Contact sensitisation	German adults (population-based, nested case-control study)	Prevalence=40% (any contact sensitization)	Schäfer T, et al
	Danish school children (12-16 yrs)	Prevalence=15%	Mortz C, et al
Hand eczema	Swedish adults (large questionnaire survey)	Prevalence=8% (including mild cases)	Meding B, et al
	Swedish school children (16-19 yrs)	Point prevalence=4%,1-year prevalence=10%	Yngveson M, et al
	Danish school children aged 12-16 yrs	Point prevalence=3%,1-year prevalence=9%	Mortz C, et al
Psoriasis	Summary of 18 population-based studies within Europe	Point prevalence=1.7% Cumulative incidence=2.1%)	Radulescu M, et al

 

Source: Modified from H. Williams et al. Epidemiology of skin diseases in Europe Eur J Dermatol 2006;16:212-218

 

 

Table 5.11.2. Prevalence of examined skin disease in Lambeth

 

Inflammatory skin diseases

 

Atopic Dermatisis

Atopic eczema (atopic dermatitis) is a chronic inflammatory itchy skin condition that in most cases develops during in early childhood. It is typically an episodic disease of exacerbation (flares, which may occur as frequently as two or three times per month) and remissions and may be continuous in some cases. Atopic eczema often has a genetic element that leads to the breakdown of the skin barrier. This makes the skin susceptible to trigger factors - including irritants and allergens - which can make the eczema worse. Many cases of atopic eczema clear or improve during childhood, whereas others persist into adulthood. Some children who have atopic eczema will go on to develop asthma and/or allergic rhinitis; this sequence of events is sometimes referred to as the ‘atopic march’ Although atopic eczema is not always recognised by healthcare professionals as a serious medical condition, it can have a significant negative impact on the quality of life for children, as well as for their parents and carers (NICE clinical guideline).

Surveys of specific skin diseases such as childhood eczema (atopic dermatitis) suggest that, like asthma and hay fever, is a major problem within Europe, affecting around 10% of all children. The highest rates (around 20%) are observed in Scandinavia and UK, whilst the lowest rates of around 5% are found in Southeastern Europe. The reasons for this North- West/South-East gradient are unclear.

Prevalence studies of children in temperate developed countries suggest an overall cumulative prevalence of between 5% to 20% by the age of 11 (Kay et al, 1994; Schmied and Saurat, 1991). Point prevalences of visible dermatitis in populations of similar ages yield values approximately half of those for a history of never having had atopic eczema (Williams et al, 1994b) compatible with the fluctuating nature of the disease. Data on the prevalence of severe disease is scanty but it is likely that most cases are mild and can be managed with simple treatments. In a study of 695 school children in London, where 8.5% were known to have visible atopic eczema, 60% of eczema cases were considered to be very mild by the examining physician (i.e. required only a moisturizer), 24% were mild (requiring a moisturizer and weak topical corticosteroid) and 16% were moderate or severe (requiring stronger topical preparations and a physician’s supervision) (Williams et al, 1995). Prevalence estimates for adults suggest an overall frequency of atopic eczema of between 1.2% to 10% (Rea et al, 1976; Johnson, 1978; Herd et al, 1994).

Comparisons between different studies are limited, as diagnostic criteria suitable for epidemiological studies of atopic eczema have only been developed recently (Williams et al, 1994b). Even allowing for changes in the diagnostic fashion, there is reasonable direct and indirect evidence to suggest that the prevalence of atopic eczema has increased two- to three-fold over the last 30 years. The precise reasons for this increase in disease is not known but it is likely that environmental factors associated to urbanization are to be considered asimportant.

Atopic eczema in childhood shows a striking social class gradient for both reported and examined disease, (Williams et al, 1994a) with higher rates in socio-economically advantaged groups and smaller families. Ethnic group may be an important factor for the expression of atopic eczema. A recent study has found that the prevalence of atopic eczema (measured in three different ways) was twice as common in London born Afro-Caribbean children when compared to their white counterparts. However, studies of Asian children in Leicester showed that, although they are three times as likely to be present in specialist clinics than white children, no differences in prevalence rates were seen in a community survey (Neame et al, 1995).

Although there are no recent national prevalence studies of atopic eczema in the UK, data for examined eczema from a national birth cohort study (the National Child Development Study or NCDS) pointed to considerable variation in disease prevalence and region, with higher rates in the South East and industrialized Midlands and lower rates in Wales and Scotland.

 

Contact dermatitis and other eczemas

The terms dermatitis and eczema are synonymous and refer to a characteristic reaction pattern of the skin to a range of external and internal factors. However, the term dermatitis is usually used to denote an exogenous process, such as contact dermatitis which may or may not be related to occupational exposure, whereas the term eczema refers to an endogenous disease such as atopic or seborrhoeic eczema.

Contact dermatitis refers to either:

- irritant contact dermatitis (e.g. frequent exposure to mild irritant soaps seen in trainee nurses or hairdressers)

- allergic contact dermatitis, where subjects develop a delayed type of allergic response to certain potentially sensitizing substances such as metals in piercing (see Focus Box), perfumes and other cosmetics, preservatives and rubber compounds.

 

FOCUS BOX Piercing and allergic contact dermatitis   Piercing practices are steadily growing among young people, and, with them, the concern about the associated allergy risk.   Most body piercing jewellery is made of metal, usually stainless steel, gold, titanium, platinum or alloys. Even if stainless steel rarely causes allergic skin reactions some stainless steel products are not “nickel-free”. Gold itself is often combined with nickel or other metals to make alloys that have improved hardness and durability. Moreover, jewellery with a high carat rating is commonly paired with less expensive studs or earring backs made of nickel and plated with a thin and imperfect layer of precious metals.   Metallic piercing with intense linear irregularities on their surface and which have lack of resistance to sweat corrosion are able to release metallic ions in the local tissue and generate several types of adverse effects in the human body, including allergic contact dermatitis (ACD) (CRF Azevedo, 2003). ACD is characterized by rash in the skin which is usually very itchy and consists of redness, scaling, fissuring, vesicles, and lichenification. In addition to primary eruptions at the site of contact, secondary eruptions might occur on the flexor surfaces of the arms and elbows (CG Mortz and KE Andersen, 1999; DV Belsito, 1999).   Nickel allergy is the most common and has a great socio-economic impact. The European Surveillance System on Contact Allergies (ESSCA) linking dermatological departments from 11 European countries was founded with the aim of providing scientific information necessary for primary prevention,. In the year 2004, altogether 11,643 patients were patch tested and the highest sensitization prevalence (32.2 %) for nickel was observed consistently for Italian departments; on the other side of this spectrum, the lowest percentage positive for nickel (9.7%) were reported in the Danish department (The ESSCA Writing Group, 2008).   It is estimated that between 10% and 15% of women and 2-5% of men in Europe are nickel-sensitised, thus, the danger of a customer suffering bad reactions from a non-conforming product is significant. The significant differences in prevalence between females and males correlates with the much higher prevalence of body piercing among women, particularly in European cultures. The 30–40% of nickel-sensitive people develop hand eczema that may be recurrent, chronic and severe, and might affect work ability (C Lidén et al, 2001). Moreover, nickel allergy can be so severe as to induce asthma (LM Koenig et al, 1999). In population studies from Scandinavian countries, the prevalence of nickel allergy among young females with pierced skin has varied from 13 to 20% in the 1980s (B Larsson-Stymne and L Widström, 1985), while in the 1990s it was reported to be roughly around 30% (L Dotterud and E Falk, 1994). In Finland, the occurrence of nickel sensitivity in female university students increased from 13 to 39% during the 1985–1995 period (L Mattila et al. 2001).   Available studies supported the point of view that the risk of becoming allergic to piercing is higher depending on the number of piercing applied and if the piercing is practiced before 20 years of age (L Dotterud and E Falk, 1994). Sensitivity has even been shown to develop in infants who have their ears pierced within the first few weeks of life (AA Fisher, 1991).   Once an allergy to nickel has been acquired, it generally lasts for life. An individual who has become sensitized to nickel, when re-exposed to nickel ions might have an allergic response within a matter of hours and at a much lower concentration of nickel than that required for inducing sensitization. Moreover, it has been demonstrated that small pieces of nickel and other metals remain in the skin lesions of pierced earlobes long after the studs have been removed. The researcher hypothesized that nickel was retained in the tissues for a mean of hundreds of days (H Suzuki, 1998). For this reason, the physical persistence of allergen can cause prolonged irritation and various cutaneous manifestations long after a patient stops wearing the nickel-releasing ear piercing.   In addition, there is emerging evidence that other metals such as chromium, cobalt, gold, platinum and palladium are also sensitizing agents. The ESSCA data revealed a percentage of European people allergic to cobalt chloride which varied from 1.1% in Denmark to 17.6% in Italy, and to potassium dichromate from 1.3% in Sheffield (UK) to 9.1% in Liverpool (UK) (The ESSCA Writing Group, 2008). In a Swedish girls group (956), a total of 44 (4.6%) had contact allergy to both nickel and cobalt, whereas 7 (0.7%) had contact allergy to cobalt (B Larsson-Stymne and L Widström, 1985). Evidence that ear piercing increases the risk of gold sensitization is that there were significantly more positive reactions to gold chloride in the patients with pierced ears than in those without pierced ears (T Nakada et al, 1997). In Portugal, contact allergy to gold sodium thiosulfate (0.78%) was found in 23 patients; all the reactors were women and had their ears pierced with gold earrings (R Silva et al, 1997). Silver may also cause problems such as localized argyria; this lesion has been typically associated to embedded jewellery. The skin is believed to become discovered from the leaching of silver with formation of silver salts (LM Koenig et al, 1999). Last but not least, as most patients with strong sensitization to nickel also react to other elements such as palladium because of cross-reactivity, piercing posts that do not leach nickel but which contain other elements such as palladium do not represent a safe alternative.   There is a widespread unanimity among dermatologists that the main way in which sensitization can be induced appears to be by contact with a high concentration of sweat-soluble nickel from a localized area. In the case of piercing, where the duration of exposure may occur for an entire life, the chronic exposure to a low concentration of allergenic metal in the alloy might be sufficient to elicit a response. On this basis, the European Directive 94/27/EC limited the content of nickel in products where intimate and prolonged skin contact will result in solubilization of nickel at a rate exceeding 0.5 µg/cm2/week. It should be noticed that the 0.5 µg Ni/cm2/week release rate is likely not to protect 100% of sensitized people from ACD elicitation. However, clinical data indicate that the vast majority of sensitized individuals would not experience ACD at this level of nickel release, whilst the vast majority of individuals not previously sensitized require substantially higher concentrations than 0.5 µg Ni/cm2/week to be released into the skin for sensitization to occur. The Directive represented the instrument for the primary and secondary prevention of nickel ACD. Many of the major suppliers have included nickel in their quality control programme and are trying to follow the regulation. Since some years have elapsed from the Directive emanation, one of the chief questions is “has the limitation had a real impact in reducing allergies?” Actually, some reports indicate a decrease in the sensitization rate to nickel. Among Danish children aged 0–18 , nickel allergy decreased significantly from 24.8% to 9.2% over a 12-year period (CS Jensen et al, 2002). In 2002-2003, the Swedish market showed that only 8% of the tested piercing posts released nickel compared to a percentage of 25% in 1999 (C Lidén and K Norberg, 2005). In a study published in 2003, nickel sensitization was found to have decreased significantly from 36.7% to 25.8% among German women below 30 years over a 9-year period (A Schnuch, and W Uter, 2003). In the USA, where no nickel regulation has been introduced, nickel continues to be responsible for clinical disease among youngsters (SH Nguyen et al, 2008). In other countries the situation is different. In Italy, in 2005, the percentage of subjects living in Rome allergic to nickel contained in cheap jewellery was the same as that found in 1994 and a part of the jewellery market was not yet in compliance with the law standards (B Bocca et al, 2007). Similarly, in Finland, in the years 1995–97 and 2000–02 the patch tests revealed percentages of 20.8% and 21.9 % for nickel allergy, thus testifying that the frequency of allergy had remained at the same level (T Hasan et al. 2005).     From an experimental point of view, alloys used for piercing are mostly uncharacterized especially for the content of new emerging metals; the metal amount from piercing that penetrates the skin and transports mechanisms in the human body is almost unknown. Moreover, we little is known about other health effects of piercing, in particularly about long-term effects. Consequently, the importance of efforts in collecting and analyzing data to create a common base of knowledge about this emerging health problem is definitely important for obtaining an overview of the dangers and adopt prevention programs. Moreover, the phenomenon is so widespread that its observation and understanding represent a challenge that stimulates researchers, doctors, parents, teachers and the young people themselves. The identification of new metals as significant contact sensitizers can be the basis for the development of standardized patch tests, in vitro predictive tests, in vitro skin absorption assays and chemical methods that in the future could be available for dermatologists, medics and scientists. Moreover, the knowledge about the occurrence of metals in products and the concentration of metals that does not induce an allergic response and does not penetrate the skin might be the basis for labelling products or use concentration limitation not only for nickel but also for new allergens. Alternatively, new chemical formulations of alloys with new candidate materials for ear piercing with an higher corrosion resistance and also a non-toxicity pattern could be a part of future outcomes.   In addition. gaining more information on the chemical risk induced by metals at pierced sites will assist in reviewing some aspects related to the piercing industry, in particular those regarding toxicity requirements and could be a tool for the decision-makers to improve and reinforce the actual legislation.   References   CRF Azevedo, Characterisation of metallic piercings, Engineering Failure Analysis, 2003;10:255–263. DV Belsito, Allergic contact dermatitis. In: Fitzpatrick's dermatology in general medicine, IM Freedberg, AZ Eisen, K Wolff, KF Austen, LA Goldsmith, SI Katz, TB Fitzpatrick (eds), 5th ed. New York:McGraw-Hill, 1999:1447-1461. Bocca B, Forte G, Senofonte O, Violante N, Paoletti L, De Berardis B, Petrucci F, Cristaudo A. A pilot study on the content and the release of Ni and other allergenic metals from cheap earrings available on the Italian market, Science of the Total Environment, 2007;388:24-34. L Dotterud, E Falk, Metal allergy in north Norwegian schoolchildren and its relationship with ear piercing and atopy, Contact Dermatitis, 1994;31:308–313. AA Fisher, Nickel dermatitis in children, Cutis, 1991;47(1):19-21. Hasan T, Rantanen T, Alanko K, Harvima RJ, Jolanki R, Kalimo K, Lahti A, Lammintausta K, Lauerma AI, Laukkanen A, luukkaala T, Riekki R, Turjanmaa K, Varjonen E, Vuorela AM, Patch test reactions to cosmetic allergens in 1995–1997 and 2000–2002 in Finland – a multicentre study, Contact Dermatitis, 2005;53:40–45. CS Jensen, S Lisby, O Baadsgaard, A Vølund, T Menné, Decrease in nickel sensitization in a Danish schoolgirl population with ears pierced after implementation of a nickel-exposure regulation, British Journal of Dermatology, 2002;146:636–642. LM Koenig, M Carnes, Body Piercing. Medical Concerns with Cutting-Edge Fashion, Journal of General Internal Medicine 1999;14(6):379–385. B Larsson-Stymne, L Widstrom, Ear piercing–a cause of nickel allergy in schoolgirls?, Contact Dermatitis,1985;13:289–293. C Lidén, M Bruze, T Menné, Chapter 41 Metals. In: Textbook of Contact Dermatitis, RG Rycroft, T Menné, PJ Frosch, J-P Lepoitterin (eds), 3rd ed. Berlin:Springer, 2001:935–950. C Lidén, K Norberg, Nickel on the Swedish market. Follow-up after implementation of the Nickel Directive, Contact Dermatitis, 2005;52:29–35. L Mattila, M Kilpeläinen, EO Terho, M Koskenvuo, H Helenius, K Kalimo, Prevalence of nickel allergy among Finnish university students in 1995, Contact Dermatitis, 2001;44(4):218-23. CG Mortz, KE Andersen, Allergic contact dermatitis in children and adolescents, Contact Dermatitis, 1999;41:121-130. T Nakada, M Iijima, H Nakayama, HI Maibach, Role of ear piercing in metal allergic contact dermatitis, Contact Dermatitis, 1997;36:233– 236. SH Nguyen, TP Dang, C Macpherson, H Maibach, HI Maibach, Prevalence of patch test results from 1970 to 2002 in a multi-centre population in North America (NACDG), Contact Dermatitis, 2008,58:101–106. A Schnuch, W Uter, Decrease in nickel allergy in Germany and regulatory interventions, Contact Dermatitis, 2003; 49:107–108. R Silva, F Pereira, O Bordalo, E Silva, A Barros , M Gonçalo,  T Correia, G Pessoa, A Baptista, M Pecegueiro, Contact allergy to gold sodium thiosulfate. A comparative study, Contact Dermatitis, 1997;37(2):78-81. H Suzuki, Nickel and gold in skin lesions of pierced earlobes with contact dermatitis: a study using scanning electron microscopy and x-ray microanalysis, Archives of Dermatological Research, 1998;290(10):523-7 The ESSCA Writing Group. The European Surveillance System of Contact Allergies (ESSCA): results of patch testing the standard series, 2004. Journal of the European Academy of Dermatology and Venereology, 2008;22(2):174–181.

 

 

 

Although both mechanisms may occur simultaneously, distinction between the two requires further investigation by means of patch testing, a process whereby a standard battery of known allergens is applied in non-irritant concentrations on the subject’s back and read 48 to 96 hours later. If the subject is found to be positive to a particular substance which is clinically relevant to that person’s dermatitis, then complete avoidance of that substance offers the opportunity of a permanent cure.

Other eczemas in this section refer to any eczema that is not contact eczema or atopic eczema. Examples are seborrhoeic eczema, discoid eczema, asteatotic eczema, pompholyx eczema, varicose eczema, photosensitive eczema and lichen simplex. Detailed prevalence rates for the various endogenous eczemas are not available, but a study suggested that around 1% of the population had clinically significant eczema that was not atopic eczema or contact dermatitis (Johnson, 1978). Seborrhoeic dermatitis was recorded separately in that study, while clinically significant disease was found to affect 2.8% of the population, mainly adults. Asteatotic eczema may be especially common in old age, affecting around 29% of those in residential old people’s homes (Weismann et al, 1980).

Overall estimates of the prevalence and incidence of contact dermatitis in the general population are scarce, whereas a number of studies have looked at special groups such as occupations at high risk of disease. The Lambeth study found a bimodal distribution of eczema prevalence thought to warrant medical care with 7.3%, 3.4% 8.9% and 3.8% in the following age groups:15–24, 25–34, 35–54 and 55–74, respectively (Rea et al, 1976). This study did not distinguish between endogenous and contact eczema. Younger ages may also suffer from contact dermatitis and a study in Sweden found that 9% of school girls had nickel allergy, with the highest rates in those with pierced ears (Larsson-Stymne and Widstrom, 1985).

Age-specific prevalence showed a bimodal distribution to the Lambeth study probably corresponding to a peak of irritant dermatitis occurring in housewives in their 20s and occupational hand eczema in men and women in the 40 to 60 years of  age group (Rea, 1976).

A study of an unselected population of Danish adults found that 15.2% were allergic to one or more

substances when patch tested but the proportion with clinically relevant dermatitis was not clear (Nielsen and Mennè, 1992).

Irritant and allergic contact dermatitis are also a serious problem affecting around 10% of adults in Europe.

Hand eczema represents one of the four most common occupationally-related diseases, accounting for substantial lost earning potential in otherwise young healthy populations (van Coevorden et al, 2004).

 

Psoriasis

Psoriasis is a common, chronic, relapsing, inflammatory skin disorder with a strong genetic basis. The plaque type is the most common, although several other distinctive clinical variants of psoriasis are recognized. Plaque psoriasis is most typically characterized by circular-to-oval red plaques distributed over extensor body surfaces and the scalp. The plaques usually exhibit scaling as a result of epidermal hyper-proliferation and dermal inflammation. The extent and duration of the disease is highly variable from patient to patient, and up to 10-20% of patients with plaque psoriasis also experience psoriatic arthritis. Acute flares or relapses of plaque psoriasis may also evolve into more severe diseases, such as pustular or erythrodermic psoriasis.

Psoriasis affects 1–5% of Europeans overall, with rates as high as 6% in France and Germany (Fouere et al, 2005). The disease afflicts men and women equally and is present in all races and socio-economic classes and usually begins in early adulthood. Heredity is strongly involved in the pathogenesis, and a series of genetic susceptibility loci have been described.

Examination of available population-based studies reveals prevalences ranging from 0.2% to 4.8%. The highest prevalence, observed in Norway, was obtained by relying on ascertainment by questionnaire without validation of positive responses. In another study from Denmark, after validation of a subset of positive questionnaire respondents by dermatological examination, prevalences were adjusted downward by 25%. With the exception of the Norwegian questionnaire study, the highest reported incidences in Europe have been in Denmark (2.9%) and the Faeroe Islands (2.8%), with the average for northern Europe being around 2% (Gudjonsson and Elder, 2007).

 

Acne

Acne is so common as to be almost universal during teenage years. Yet surveys have suggested that only few affected individuals receive good medical advice regarding the most appropriate treatment that can prevent lifelong facial scarring. Acne vulgaris is a very common condition characterized by papules, pustules, comedones (blackheads) and scars. It is caused by a combination of factors such as excessive and abnormal grease production, a bacterium (Propionibacterium acnes) and other abnormalities of the skin which lead to plugging of pilo-sebaceous openings. Mild degrees of acne are extremely common among teenagers and some have even considered it as a physiological disorder. In discussing disease prevalence it is essential that some form of further breakdown according to disease severity is considered. It is also important to realize that whilst these severity gradings are reasonably objective, they do not usually take into account the points of view of the sufferer. Acne vulgaris is a common skin disease that affects 85-100% of people at some time during their lives.

 

Rare skin diseases

Historically, skin diseases have been mainly perceived as caused by internal disease (“skin as a mirror of the body”). While it is clear that this extrapolation was generally untenable, it still holds true for some skin disorders. Metabolic diseases (e.g. diabetes, hyperlipidemias, porphyrias, amyloidosis) are often accompanied by highly specific skin symptoms which may alert the physician to the correct diagnosis; the same is true for a spectrum of cardiovascular, pulmonary and

digestive tract diseases (e.g. dermatitis herpetiformis accompanying gluten sensitive enteropathy) and cancer of internal organs which may be associated to pathognomonic paraneoplasias of the skin.

Systemic autoimmune disorders – collagen vascular diseases, systemic vasculitides – are regularly associated to skin symptoms. The skin is also the target of organ specific autoimmune diseases (e.g. alopecia areata, vitiligo) and of autoimmune bullous disorders (pemphigus and pemphigoid groups).

Therefore, it is quite easy to forget the importance of rare skin diseases 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 considering 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. This allows to have a sufficient number of patients to conduct reliable studies e.g., the mapping of molecular defects underlying genetic skin diseases that may greatly profit from such joint European enterprises (see also Chapter 7 on “Rare Diseases”).

 

Skin cancers

Melanoma and non-melanoma (basal and squamous cell carcinoma) skin cancer (NMSC) are now the most common type of cancer in fair skinned populations. The incidence of skin cancer has reached epidemic proportions (Diepgen and Mahler, 2002; Boyle et al, 2004).

 

Non-Melanoma skin cancer

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 (Table 5.11.3).

 

Table 5.11.3. Age-standardized rates of non melanoma skin cancer in European fair skinned population (per 100 000).

 

 

There is little information systematically collected and available regarding NMSC in Europe. In Trentino, Italy, the Skin Cancer Registry calculated (for the period 1993–1998) that an incidence rate of 88 per 100 000 for BCC, of 29 per 100 000 for SCC and 14 per 100 000 for melanoma (de Rijke et al, 2000). This tendency was confirmed in Izmir, Turkey, where nearly half the lesions appeared on the face and, while SCC was equally common in men and women, BCC were nearly three times more frequent in men (Ceylan et al, 2003).

In Vaud, Switzerland, BCC was the most common form of skin cancer reported in both men and women. Its incidence has been rising steadily since registration was introduced in the mid 1970s (Levi et al, 2001). In Sweden, 39 805 SCC were registered between 1961 and 1995 (Levi et al, 2001). Incidence rates increased substantially in men (by 42%) and in women (by 146%) during this period and interpretation of mathematical models led the authors to conclude that these increases could probably be explained by increased cumulative sun exposure and increasing incidence among the elderly (Wassberg et al, 2001).

Between 1978 and 1995, the Slovakian Cancer Registry registered 38 629 cases of NMSC (19 600 in men and 19 029 in women). During this period, incidence rates of BCC increased by 70.4% in men and 65% in women, while incidence rates of SCC increased by 13.5% in men and 18.8% in women. Head and neck were the most common sites (84.2% BCC and 74.7% SCC) followed by the

trunk for BCC (17% in men and 11% in women) and upper limbs for SCC (12% in men and 12.5% in women) (Plesko et al, 2000).

Mortality from NMSC is almost always from SCC, a form of cancer whose risk is strongly linked to cumulative lifetime sun exposure (Rosso et al, 1996). NMSC mortality in Europe presents an entirely different picture than melanoma. The rates are higher in men and women in Southern European countries (Greece, Spain, Portugal and Italy) and low in the Nordic countries (Boyle and Smans, 2003).

Both basal cell carcinoma and squamous cell cancer are cured by adequate surgical removal. The capacity of many current health care systems to cope with such surgical demand, associated with skin cancers, is currently stretched to a maximum in some European countries due to the increasing incidence of NMSC.

 

Melanoma

Melanoma is the most serious form of skin cancer, and its incidence has been rising steeply in the fair skinned population over the last 30 years (doubling the number of cases every 10-15 years), probably due in part to an increased leisure exposure to the sun. It is estimated that in 2000 there were 132 000 cases of melanoma diagnosed world-wide and 37 000 deaths caused by melanoma. In Europe, it is estimated that in 2000 there were 35 000 cases of melanoma diagnosed and 9000 deaths caused by melanoma. The annual world-wide melanoma burden is split unevenly between high-resource countries (104 000 cases and 25 000 deaths) and low- and medium-resource countries (28 500 cases and 12 000 deaths) (Ferlay et al, 2001). The death incidence ratio is strikingly different in these categorizations.

In Europe, during the 1990s, incidence rates were higher in northern and Western Europe whereas mortality was higher in men in eastern and southern Europe. Mortality rates have been rising steadily and in Northern Europe a deceleration has been taking place since the early 1980s. Mortality rates have also leveled off in Western Europe whereas in eastern and southern Europe both incidence and mortality are still rising (De Vries et al, 2003). The net effect is that melanoma mortality rates in the mid-1990s (1993–1997) are higher in Nordic countries and lower in southern European populations, such as Greece, Spain and Portugal (Boyle and Smans, 2003).

Melanoma is at least to some degree preventable, but approaches to educate the public on the dangers of sunbathing have been variable, ranging from unsatisfactory 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. Although melanoma is curable when recognised at an early stage, availability of facilities for detecting such early cases varies widely within relatively short distances in Europe.