A recent review has summarized the global distribution of podoconiosis. In some areas of Ethiopia, the prevalence is as high as 4%. The incidence of podoconiosis increases with age, likely due to cumulative exposure to irritant soil. It is very rare to see podoconiosis in the 0–5 year old age group, and the incidence rapidly rises from 6 to 20 years of age, with the highest prevalence after 45 years of age. Podoconiosis is most commonly seen in higher altitude areas with volcanic soil, and it is estimated to affect 4 million people worldwide. Productivity losses associated with the disease are significant. In Ethiopia (where 1.6 million people are estimated to be affected), the condition is thought to have caused US $200 million in lost productivity per year in 2004. History
After parasitic filariae were discovered to be an important cause of tropical lymphedema in the 19th century, early investigators assumed that filariae were the sole cause of lymphedema in the tropics. It was later discovered that the distribution of tropical lymphedema and filariasis did not perfectly overlap, and researchers began to recognize that some forms of tropical lymphedema were not associated with filariasis. Ernest W Price, a British surgeon living in Ethiopia, discovered the true etiology of podoconiosis in the 1970s and 1980s by studying the lymph nodes and vessels of those afflicted with the disease. Using light microscopy, he observed macrophage cells laden with micro-particles in lymph nodes of the affected extremity.
Prevention
Elimination of podoconiosis relies on prevention with widespread shoe implementation, stringent foot hygiene, and floor coverings. Community-based initiatives are crucial to achieving elimination of this disease. In Ethiopia, The Mossy Foot Treatment and Prevention Association (now Mossy Foot International) works to transform patients into community podoconiosis agents who in turn visit patients, teach basic treatment techniques such as foot hygiene, and educate families about the disease. This model has been adapted by several other non-government groups as they have started programs in other regions of Ethiopia. Treatment
The cornerstone of prevention and treatment of podoconiosis is avoidance of exposure to irritant soils. Wearing shoes in the presence of irritant soils is the primary method of exposure reduction. In Rwanda, a country of high disease prevalence, the government has banned walking barefoot in public, in order to prevent podoconiosis and other soil-borne diseases. Increasing the availability of footwear must be coupled with education on the benefits of wearing shoes as cultural influences, such as barefoot traditions, can hinder widespread use of footwear.Once the disease has developed, rigorous foot hygiene including daily washing with soap and water, application of an emollient, and nightly elevation of the affected extremity has been shown to reduce frequency of acute attacks. Nodules will not resolve with these conservative measures, although surgical removal of the nodules can be performed. Epidemiology
Podoconiosis is most frequently seen in the highland areas of Africa, India, and Central America. The highest prevalence is seen in Uganda, Tanzania, Kenya, Rwanda, Burundi, Sudan, and Ethiopia.