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. Signs and symptoms
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 diseases 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. Psychological consequences
As a result of its appearance, podoconiosis can cause social stigmatization and discrimination. People with podoconiosis also report a lower quality of life than people in  similar neighborhood circumstances except without podoconiosis and also higher levels of mental distress and depression.
Pathophysiology
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. Diagnosis
Differential diagnosis
The differential diagnosis for podoconiosis includes other causes of tropical lymphedema, such as filariasis or leprosy, and mycetoma pedis.While filariasis is generally unilateral, podoconiosis affects the legs bilaterally albeit asymmetrically and in an ascending manner. Podoconiosis very rarely affects the groin while filariasis frequently involves the groin: a high ratio of lymphoedema/hydrocele cases in an area suggests podoconiosis as the dominant cause of lymphedema. In some cases, the history and clinical presentation alone are unable to differentiate between the two causes of tropical lymphedema. Local epidemiology can also be a clue to diagnosis, as podoconiosis is typically found in higher altitude areas with volcanic soils while filariasis is common in low-lying areas where mosquitos are prevalent. Blood smears for identification of microfilariae and antigen detection techniques can be helpful in the diagnosis of lymphatic filariasis.Lepromatous lymphedema can also mimic podoconiosis clinically, but the former will have loss of sensation in the toes and feet, thickened nerves, and trophic ulcers. Other causes of lymphedema include Kaposi sarcoma, mycetoma, and elephantiasis nostras verrucosa.