Podoconiosis, also known as mossy foot, is a non-infectious type of lymphatic filariasis and caused by years of barefoot exposure to red clay soil. It affects about 5%-10% of the population in highland tropical areas (i.a. Africa, Central America and north-west India) with sticky red soil rich in silicates derived from volcanic deposits. Ethiopia is one of the countries most heavily affected with an estimated 1 million people, mostly subsistence farmers, affected. Enduring exposure to irritant mineral particles in the soil triggers inflammatory changes within the lymphatic system in the legs. Early symptoms commonly include itching of the skin of the forefoot and a burning sensation in the foot and lower leg. This is followed by swelling and hyperkeratosis with the formation of moss-like papillomata, and after years of exposure elephantiasis. However, not everyone who lives and works barefoot on irritant soils becomes affected, and there is strong evidence for a genetic component to disease causation. Effective, simple and inexpensive treatment consists of lymphedema management (i.e. foot hygiene, emollient, bandaging, exercises/massage and protective footwear) to reduce the swelling and improve quality of life.
Podoconiosis has a great economic impact (i.e. lost productivity and medical costs) and may cause great social stigma. Affected persons often cannot work, are excluded from school, local meetings, churches and mosques, and barred from marriage with unaffected individuals. Social rehabilitation is therefore vital. It includes training for affected persons in skills that enable them to generate income without contact with irritant soil.
Elimination of podoconiosis is likely to be feasible. The fact that the disease is not infectious makes elimination easier. The use of protective footwear is an effective intervention for prevention of podoconiosis. Consistent use of footwear, regular foot hygiene and covering floors are the key preventive strategies against podoconiosis. However, financial constraints, lack of appropriate footwear for wet and dry seasons and sociocultural factors may affect the availability and use of footwear. Innovative approaches are needed to make footwear affordable and appropriate to local activities and seasonal patterns.