Podoconiosis: A Possible Cause of Lymphedema in Micronesia

Podoconiosis is a type of tropical lymphedema sharing some clinical characteristics with lymphatic filariasis. Also referred to as endemic non-filarial elephantiasis, podoconiosis is a non-infectious disease from barefoot exposure to irritant red clay soil of volcanic origins. Podoconiosis is most common in Ethiopia and has also been reported in many other countries, but not in the Pacific Islands. Lymphatic filariasis is endemic in the Pacific Islands and was historically reported as elephantiasis in Micronesia. It was considered to have been eradicated in Guam and the Northern Mariana Islands following World War II. A small number of patients in Saipan exhibited characteristics of lymphatic filariasis but were seronegative for filariasis. Clinical examination of these patients matched podoconiosis much more closely than filariasis. Moreover, these patients reported a history of chronic barefoot exposure to irritant red clay soil and a prodrome characteristic of podoconiosis. While this study is limited to several cases, the results suggest that podoconiosis could be considered a cause of non-filarial lymphedema in Saipan and perhaps other islands in Micronesia. Preventive patient education is focused on discouraging barefoot exposure to red clay soils, particularly in those with a family history of lymphedema. Early recognition of the possibility of podoconiosis would allow appropriate treatment and prevent progression to later debilitating stages of the disease.