Podoconiosis

Podoconiosis, also known as nonfilarial elephantiasis, is a disease of the lymphatic vessels of the lower extremities that is caused by chronic exposure to irritant soils. It is the second most common cause of tropical lymphedema after lymphatic filariasis, and it is characterized by prominent swelling of the lower extremities, which leads to disfigurement and disability. Methods of prevention include wearing shoes and using floor coverings. Mainstays of treatment include daily foot hygiene, compression bandaging, and when warranted, surgery of overlying nodules. Podoconiosis, also known as nonfilarial elephantiasis, is a disease of the lymphatic vessels of the lower extremities that is caused by chronic exposure to irritant soils. It is the second most common cause of tropical lymphedema after lymphatic filariasis, and it is characterized by prominent swelling of the lower extremities, which leads to disfigurement and disability. Methods of prevention include wearing shoes and using floor coverings. Mainstays of treatment include daily foot hygiene, compression bandaging, and when warranted, surgery of overlying nodules. Podoconiosis causes bilateral yet asymmetrical leg swelling with overlying firm nodules. Early on, symptoms may include itching, tingling, widening of the forefoot, and swelling which then progress to soft edema, skin fibrosis, papillomatosis, and nodule formation resembling moss, giving rise to the disease's alternate name of 'mossy foot' in some regions of the world. As with other forms of tropical lymphedema, chronic disease can lead to rigid toes, ulceration, and bacterial superinfection. During acute episodes of adenolymphangitis, patients may develops fevers, extremity warmth, redness, and pain. These episodes are extremely debilitating and account for many days of activity and productivity loss each year. As a result of its appearance, podoconiosis can cause social stigmatization and discrimination. People with podoconiosis also report lower quality of life than neighborhood controls and higher levels of mental distress and depression. According to the World Health Organization 'Evidence suggests that podoconiosis is the result of a genetically determined abnormal inflammatory reaction to mineral particles in irritant red clay soils derived from volcanic deposits'. The pathophysiology of podoconiosis is a combination of genetic susceptibility, possibly through associations with HLA-DQA1, HLA-DQB1, and HLA-DRB1 variants, and a cumulative exposure to irritant soil. In susceptible individuals, irritant soil particles penetrate the feet and collect in lymphatic vessels. Over time, chronic inflammation within the lymphatic vessels leads to fibrosis and occlusion. The differential diagnosis for podoconiosis includes other causes of tropical lymphedema, such as filariasis or leprosy, and mycetoma pedis.