Elephantiasis-Lymphatic Filariasis
Elephantiasis is chronic lymphoedema from a chronic lymphatic filariasis. Lymphatic filariasis is an infection of the lymphatic system by nematode filariae. It can cause enlargement of entire legs, arms, genitals, vulva, or breasts in addition to damaging the kidneys and lymphatic system. It is caused by one of three different species of nematodes. Majority of cases are caused by Wuchereria bancrofti, but B. malayi and B. timor may also cause this infection. LF can be a severely debilitating and disfiguring disease. It affects over 120 million people in over 80 countries in the tropics and sub-tropics. According to the WHO one third of all cases are in India, another third in Africa, and the remaining third in South East Asia, the Pacific, and the Americas.
The disease is transmitted by the bite of a mosquito. Mosquitoes feed off a person with microfilariae in their blood. From there the microfilariae develop into the infectious form and migrate toward the biting parts of the mosquito. When the mosquito feeds next the larvae are transferred to the person. The filariae reside in the lymphatic system and produce microfilariae that circulate in the blood. The parasites have a “nocturnal periodicity” and can only be seen in blood that is drawn at night. In the past this made diagnosis difficult but today an antigen detection test is done to determine the presence of parasite antigen in the blood which does not vary with time of day.
The presentation of LF can vary greatly from an asymptomatic infection to a debilitating/disfiguring disease. The variation is due to the reaction of the individual’s immune system and the parasite strain. Clinical symptoms are a result of local inflammation and immune response in addition to the direct damage of the parasite to the lymphatic system. The clinical features present both acutely and chronically. Acute features include filarial fever, limb lymphadenitis/lymphangitis, and epididymo-orchitis. The fever lasts three to seven days and is accompanied by chills, rigor, arthralgias, head ache, and sometimes delirium. The lymphadenitis/lymphangitis is extremely painful and can form abscesses. Epididymo-orchitis is the most common presentation and may also be accompanied by scrotal oedema and or hydrocele.
Chronic LF represents the cumulative effect of the disease and its progression over many years. There is some overlap between the acute and chronic states. Hydrocele may also be a chronic condition. It should be noted that multiple tapping of the hydrocele can yield to fibrosis and abscess formation. Chronic lymphoedema, otherwise known as elephantiasis, is common. It often affects the leg in an asymmetric manner. Grade I is transient, pitting edema that is relieved with rest and elevation. Grade II is oedema, non-pitting, and the skin becomes brawny. Grade III is characterized by lymphoedema. The skin becomes thickened, hyperkeratotic, and papillomatous changes occur. Chyuria and lymphuria may also occur due to rupture of damaged lymph from the intestines or other organs into the bladder or renal pelvis. Chyuria can cause malabsorbtion and both can cause urinary obstruction.LF is treated with one dose of albendazole and either diethlycarbamazine (DEC) or ivermectin. In some high risk endemic areas whole communities are treated annually to prevent spread of the disease with the above two drug combination. Another method of prevention in endemic areas is fortifying table salt with DEC. An important principal in managing LF is to prevent further progression of lymphoedema. Much of this is done by preventing bacterial/fungal super-infections and promoting/reestablishing lymph flow to affected areas. This can be accomplished by good hygiene to limb and nails, raising the affected limb at night, exercise to promote flow, and early treatment of wounds and abrasions. Collateral channels will open if infection is prevented. Chronic hydrocele maybe treated with surgical excision. Although LF can be extremely deforming and debilitating it is a preventable and treatable condition.
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