Tropical sprue is a disease which causes a food absorption problem, especially with fat. The high risk places for catching tropical sprue are Southeast Asia and South America, and it is not normally found in Africa. The cause is not fully understood, but may be due to a viral infection, and/or from dietary factors. The symptoms are diarrhea (pale large stools), a sore tongue, loss of appetite, and weight loss. In the latter stages of the disease, a patient may develop ostemalacia (softening of the bones), peripheral neutitis, edematous swelling of the extremities, and megaloblasitic anemia. The standard treatment for tropical sprue is folic acid and cyanocobalamin. If diarrhea continues a cycle of tetracycline can be given. Anemia can be corrected by intracenous transfusions if necessary, and iron can be administered if there are any signs of iron-deficiency anemia in addition to megaloblastic anemia. Tropical sprue must be distinguished from gluten sensitivity. It is said that the damage form tropical sprue does not get as severe as that of celiac disease, but it may be very hard to distinguish the two. Arasitic infestations also need to be considered in people who have problems upon returning from underdeveloped areas.