Podoconiosis: let Ethiopia lead the way

Abstract

The history of podoconiosis (endemic, nonfilarial elephantiasis) is better described in Ethiopia then anywhere else in the world. EW Price's elegant investigations through the 1970s and 1980s described the epidemiology (1), ecology (2), pathology (3) and natural history (4) of podoconiosis among Ethiopian patients, and mapped the condition across tropical Africa (5-7). The Addis Ababa-based leprologist estimated 5% prevalence of the disease among subsistence farmers who live and work barefoot on the irritant red soil that covers approximately 18% of the surface area of Ethiopia (1-2). Histopathology indicates that colloid-sized silicate particles enter through the skin, are taken up into macrophages in the lower limb lymphatics and cause endolymphangitis and obliteration of the lymphatic lumen (3,8). Early symptoms commonly include a burning sensation in the foot and lower leg, while early changes consist of splaying of the forefoot, plantar oedema with lymph ooze, increased skin markings, hyperkeratosis with the formation of moss-like papillomata, and 'block' (rigid) toes. Later, the swelling may be one of two types; soft and fluid ('water-bag' type); or hard and fibrotic ('leathery' type), often associated with multiple hard skin nodules (4,9). Protection of the feet from the irritant clay soil through regular use of robust footwear is enough to prevent disease: podoconiosis has been eradicated from Europe simply through the use of shoes (10).