Patterns of Skin Diseases at the Community Level
A recent (unpublished) survey by the International Foundation of Dermatology designed to provide information about community patterns of skin disease in nine different countries across the world—Australia (Northwest Territory), Ethiopia, Indonesia, Mali, Mexico, Mozambique, Senegal, Tanzania, and Thailand)—and poor regions in other tropical environments from Mexico to Madagascar indicates that the following were the main skin conditions at community level:
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Scabies. Although scabies was often the commonest skin disease, it was completely absent in some regions.
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Superficial mycoses. This group of infections was usually reported as one of the three commonest diseases.
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Pyoderma. This disease was often, but not invariably, associated with scabies.
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Pediculosis. This disease was the subject of much variation but is often overlooked in surveys. Firm, community-level data on the prevalence of pediculosis are deficient; thus, this disease is not discussed further in this chapter.
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Eczema or dermatitis. Although this disease was usually unclassified, irritant dermatitis and chronic lichen simplex were often cited.
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HIV-related skin disease. This disease was reported mainly in Africa. The pruritic papular dermatitis of AIDS is a specific problem.
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Pigmentary anomalies. Three different problems were cited: hypopigmentation, often diagnosed as pityriasis alba, a form of eczema; melasma; and dermatitis caused by cosmetic bleaching agents (Mahe and others 2003).
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Acne. This disease was reported as an emerging and common problem.
These diseases are the same as those recorded in the literature described previously. Other skin conditions cited by different members of the group surveyed follow:
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Tropical ulcer. The incidence was highly variable, but tropical ulcer can account for a huge workload in primary care centers in endemic areas.
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Nonfilarial lymphoedema. This condition was mainly confined to Ethiopia.
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Onchodermatitis, filarial lymphoedema, endemic treponematoses, Buruli ulcers, and leprosy. These conditions are discussed in detail elsewhere in this book, but note that they often present with skin changes and symptoms.
According to World Bank (2002) figures for low-income populations in 2000, the estimated numbers of individuals infected with pyoderma and scabies, based on the highest prevalence figures from community surveys in the developing world, are 400 million and 600 million, respectively. Based on the lowest prevalence figures, these estimated numbers are 40 million and 50 million, respectively. For tinea capitis, the estimated number of cases based on the highest estimates of prevalence for Sub-Saharan Africa alone is 78 million.
Overall, these data suggest that significant changes could be made in reducing the burden of skin diseases by focusing on the small group of conditions, particularly infections, that 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 infections, tropical ulcers, HIV/AIDS-related dermatoses, and pigmentary disorders.
