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Chapter Skin Diseases - DCP3 - pete davidson skin disease

Chapter Skin Diseases - DCP3-pete davidson skin disease

Chapter 37
Skin Diseases
Roderick Hay, Sandra E. Bendeck, Suephy Chen, Roberto Estrada,
Anne Haddix, Tonya McLeod, and Antoine Mah?
In assigning health priorities, skin diseases are sometimes Sub-Saharan Africa, leads to a similar impact on life quality
thought of, in planning terms, as small-time players in the compared with non-HIV-related skin problems, although the
global league of illness compared with diseases that cause signif- use of antiretroviral therapy significantly improves quality of
icant mortality, such as HIV/AIDS, community-acquired pneu- life (Mirmirani and others 2002). Those findings indicate that
monias, and tuberculosis. However, skin problems are generally skin diseases have a significant impact on quality of life.
among the most common diseases seen in primary care settings Although mortality rates are generally lower than for other
in tropical areas, and in some regions where transmissible dis- conditions, people's needs for effective remedies for skin con-
eases such as tinea imbricata or onchocerciasis are endemic, ditions should be met for a number of important reasons.
they become the dominant presentation. For instance, the
World Health Organization's 2001 report (Mathers 2006) on ? First, skin diseases are so common and patients present in
the global burden of disease indicated that skin diseases were such large numbers in primary care settings that ignoring
associated with mortality rates of 20,000 in Sub-Saharan Africa them is not a viable option. Children, in particular, tend to
in 2001. This burden was comparable to mortality rates attrib- be affected, adding to the burden of disease among an
uted to meningitis, hepatitis B, obstructed labor, and rheumat- already vulnerable group.
ic heart disease in the same region. Using a comparative assess- ? Second, morbidity is significant through disfigurement,
ment of disability-adjusted life years (DALYs) from the same disability, or symptoms such as intractable itch, as is the
report, the World Health Organization recorded an estimated reduction in quality of life. For instance, the morbidity from
total of 896,000 DALYs for the region in the same year, similar secondary cellulitis in lymphatic filariasis, which may lead
to that attributed to gout, endocrine disease, panic disorders, to progressive limb enlargement, is severe, and subsequent
and war-related injuries. As noted later, those figures require immobility contributes to social isolation.
confirmation by more detailed studies, and their practical ? Third, the relative economic cost to families of treating even
application to health interventions needs to be tested. trivial skin complaints limits the uptake of therapies.
Assessing the impact of skin disease on the quality of life in Generally, families must meet such costs from an over-
comparison with that of chronic nondermatological diseases is stretched household budget, and such expenses in turn
difficult; however, the study by Mallon and others (1999), reduce the capacity to purchase such items as essential foods
which was not carried out in a developing country, compares (Hay and others 1994).
the common skin disease acne with chronic disorders such as ? Fourth, screening the skin for signs of disease is an impor-
asthma, diabetes, and arthritis and finds comparable deficits in tant strategy for a wide range of illnesses, such as leprosy, yet
objective measurements of life quality. Skin disease related to a basic knowledge of the simple features of disease whose
HIV, which may constitute an important component of the presenting signs occur in the skin is often lacking at the
skin disease burden in developing countries, particularly in primary care level.
A shortage of elementary skills in the management of skin pediculosis capitis, tinea capitis, or pyoderma (Figueroa and
diseases is a further confounding problem. A number of stud- others 1996). Those figures mirror work carried out elsewhere.
ies assessing success in the management of skin diseases in pri- For instance, in Tanzania, in a survey of two village communi-
mary care settings in the developing world find that treatment ties, Gibbs (1996) found that 27 percent of patients had a treat-
failure rates of more than 80 percent are common (Figueroa able skin disease, and once again, infections were the most
and others 1998; Hiletework 1998). An additional point, often common diseases. Overcrowding was a major risk factor in that
overlooked, is that skin diseases in the developing world are survey. A similar community-based survey in Sumatra,
often transmissible and contagious but are readily treatable Indonesia, showed a 28 percent prevalence of skin disease (Saw
(Mah?, Thiam N'Diaye, and Bobin 1997). and others 2001). What seems to influence the overall preva-
A number of common diseases account for the vast majority lence and pattern of skin conditions in certain areas is the exis-
of the skin disease burden; therefore implementing effective tence of a number of common contagious diseases, notably,
treatments targeted at those conditions results in significant scabies and tinea capitis. Hot and humid climatic conditions
gains for both personal and public health. Even where eradica- may also predispose populations to pyoderma, thereby affect-
tion is impossible, control measures may be important in ing the distribution of disease.
reducing the burden of illness; yet few systematic attempts have
been made to validate control programs for skin diseases as
public health interventions. PATTERNS OF SKIN DISEASES
PREVALENCE OF SKIN DISEASES A recent (unpublished) survey by the International
Foundation of Dermatology designed to provide information
Few studies aimed at estimating the prevalence of skin diseases about community patterns of skin disease in nine different
have been carried out in Western societies. However, Rea, countries across the world--Australia (Northwest Territory),
Newhouse, and Halil's (1976) study in Lambeth, south Ethiopia, Indonesia, Mali, Mexico, Mozambique, Senegal,
London, which used a questionnaire-based, population- Tanzania, and Thailand)--and poor regions in other tropical
centered approach backed by random examination, reveals an environments from Mexico to Madagascar indicates that
overall 52 percent prevalence of skin disease, of which the the following were the main skin conditions at community
investigators judged that just over half the cases required treat- level:
ment. Studies from developing countries have generally
adopted a more inclusive approach that uses systematic, ? Scabies. Although scabies was often the commonest skin
community-based surveys backed by examination. Published disease, it was completely absent in some regions.
figures for the prevalence of skin diseases in developing coun- ? Superficial mycoses. This group of infections was usually
tries range from 20 to 80 percent. reported as one of the three commonest diseases.
In a study in western Ethiopia, between 47 and 53 percent of ? Pyoderma. This disease was often, but not invariably, associ-
the members of two rural communities claimed to have a skin ated with scabies.
disease (Figueroa and others 1998), but when they were exam- ? Pediculosis. This disease was the subject of much variation
ined, 67 percent of those who denied having skin problems but is often overlooked in surveys. Firm, community-level
were found to have treatable skin conditions, most of which data on the prevalence of pediculosis are deficient; thus, this
were infections. However, prevalence alone does not equate disease is not discussed further in this chapter.
with disease burden. For instance, most communities recognize ? Eczema or dermatitis. Although this disease was usually
scabies as a problem because of its intractable itching and sec- unclassified, irritant dermatitis and chronic lichen simplex
ondary infection, whereas they may ignore tinea capitis, which were often cited.
is equally common among the same populations, because they ? HIV-related skin disease. This disease was reported mainly in
are aware that it follows a benign and asymptomatic course in Africa. The pruritic papular dermatitis of AIDS is a specific
many patients. problem.
Researchers agree about the main risk factors associated ? Pigmentary anomalies. Three different problems were cited:
with skin disease in developing countries, the most important hypopigmentation, often diagnosed as pityriasis alba, a form
of which appears to be household overcrowding. In primary of eczema; melasma; and dermatitis caused by cosmetic
schools in western Ethiopia, more than 80 percent of randomly bleaching agents (Mah? and others 2003).
examined schoolchildren had at least one skin disease, ? Acne. This disease was reported as an emerging and
which was usually caused by one of four conditions: scabies, common problem.
708 | Disease Control Priorities in Developing Countries | Roderick Hay, Sandra E. Bendeck, Suephy Chen, and others
These diseases are the same as those recorded in the litera- Table 37.1 Search Strategy for Therapies
ture described previously. Other skin conditions cited by dif-
Search term for
ferent members of the group surveyed follow: Disease Search term for disease treatment
? Tropical ulcer. The incidence was highly variable, but tropi- Scabies ["scabies"] ["treatment of" or
cal ulcer can account for a huge workload in primary care "ivermectin" or
centers in endemic areas. "permethrin" or
? Nonfilarial lymphoedema. This condition was mainly con- "Lindane" or
fined to Ethiopia.
"malathion" or
"benzoyl benzoate" or
? Onchodermatitis, filarial lymphoedema, endemic trepone- "crotamiton" or
matoses, Buruli ulcers, and leprosy. These conditions are dis- "sulfur"]
cussed in detail elsewhere in this book, but note that they Pyoderma or ["skin diseases, bacterial" or ["drug therapy" or
often present with skin changes and symptoms. bacterial skin "ecthyma" or "staphylococcal "prevention & control"
infections skin infections" or "impetigo" or "therapy"]
According to World Bank (2002) figures for low-income or "pyoderma" or "folliculitis"]
populations in 2000, the estimated numbers of individuals Tinea capitis: ["tinea capitis"] ["drug therapy" or
infected with pyoderma and scabies, based on the highest "therapy" or
prevalence figures from community surveys in the developing "prevention & control"]
world, are 400 million and 600 million, respectively. Based on Tinea imbricata: ["tinea imbricata.mp"]
the lowest prevalence figures, these estimated numbers are
40 million and 50 million, respectively. For tinea capitis, the Tropical ulcer ["tropical ulcer$.ti"] or
estimated number of cases based on the highest estimates of ["skin ulcer(explode)" and
prevalence for Sub-Saharan Africa alone is 78 million.
Overall, these data suggest that significant changes could be Source: Authors.
made in reducing the burden of skin diseases by focusing on Note: Terms in brackets are medical subject heading terms. If no standard medical subject
heading terms were available, databases were searched either using the title option (denoted
the small group of conditions, particularly infections, that as ".ti") or the keyword option (denoted as ".mp").
account for the bulk of the community case load. This chapter
concentrates on those conditions for which such a strategy
could be implemented--namely, scabies, pyoderma, fungal SKIN DISEASES
infections, tropical ulcers, HIV/AIDS-related dermatoses, and Scabies
pigmentary disorders. Scabies is a common ectoparasitic infestation caused by
Sarcoptes scabei, a human-specific mite that is highly prevalent
EFFECTIVE THERAPIES in some areas of the developing world. Scabies is transmitted by
direct contact. In industrial societies, it is usually seen in sexu-
In considering the evidence for effective treatment, a subgroup ally active adults, although it may also appear in the form of
of the team (Bendeck, Chen, and McLeod) undertook a data clusters of cases among the elderly in residential homes. Peaks
search to establish the evidence base for treatment of the com- of infection in communities may be cyclical. The ease of trans-
mon conditions. They carried out comprehensive searches of mission appears to depend, in part, on the parasitic load, and
the MEDLINE (1966-April 2003) and EMBASE (1980-April some patients, including the elderly, may have large numbers of
2003) databases to identify therapeutic studies on scabies, parasites present. By contrast, in healthy adults, the total para-
pyodermas, and superficial mycoses (but note that many of the site load may be low, but they, nonetheless, may suffer from
studies were performed in industrial countries). They used highly itchy lesions. The organisms can also reach high densi-
foreign-language articles if an English abstract was provided. ties in patients suffering from a severe depression of immuno-
Table 37.1 shows search terms for each of the skin diseases logical responses, as in HIV infection. In this crusted or
common in the developing world and for treatment. Norwegian form of scabies, lesions may present with atypical
The team members reviewed study titles and abstracts to crusted lesions that itch little.
select relevant articles and scrutinized the bibliographies of In developing countries, transmission commonly occurs in
selected articles to identify pertinent studies not captured in young children and infants and their mothers and is related to
the initial literature search. They defined admissible evidence as close contact, overcrowding, and shared sleeping areas. Sexual
primary therapeutic studies, based on clinical evaluation, of the contact is less important as a means of transmission. Scabies is
treatment of each disease. also a scourge of prisons in developing countries, where it is
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