About Action on Podoconiosis Association (APA) Podoconiosis (endemic non-filarial elephantiasis) is a non-infectious disease caused by exposure of bare feet to particular soil types. Left untreated, it results in progressive swelling and radical disfigurement of the lower legs and feet. Podoconiosis is mostly a disease of people who work barefoot in the fields, particularly on red clay soils in upland volcanic areas. It is thought that clay particles, absorbed through cracks and fissures in the skin of the foot, are taken up by the lymphatic system in the lower limb. These particles then appear to react directly with lymphatic vessel walls, leading to failure of the lymphatic system in the lower legs, chronic inflammatory response and elephantiasis. Podoconiosis is widespread in highland areas of tropical Africa, Central America and northern India.