Lymphatic Filariasis (LF) is caused by a microscopic worm that spread from person to person by the bite of an infected mosquito. The microscopic worms pass from the mosquito through the skin, travel to the lymph vessels and grow into adults. The adult worms then release millions of microscopic eggs called microfilariae, into the blood. People with live filarial worms in their blood can give the infection to others through mosquitoes. The microfilaria damage the lymph nodes and lymphatic vessels by which the flow of lymph fluid is impaired and causes massive lymphoedema (elephantiasis) of the legs, arms, breast, and genital area. There are no symptoms in the early stage of infection after receiving mosquito bites. This stage can last for several years. As the disease progresses the skin becomes much thickened and with overhanging folds resembling the foot of an elephant.
Cellulitis or Filarial fever is a common soft tissue infection affecting lymphoedema patients. Most commonly this occurs in the lower leg but can develop anywhere in the body. In severe infections, the inflammation can spread to the lymphatic vessels (lymphangitis) and cause damage. Frequent inflammatory episodes lead to swelling because of scarring (damage) around the lymphatic channels and will have the following symptoms.
- Pain and tenderness.
- Warmth of the affected region.
- Erythema (redness).
- Increased swelling.
- Local lymphadenitis (infection of lymph nodes).