Elephantiasis is characterized by swelling of the limbs, most often the legs, which sometimes also affects the genitals. It is from this peculiarity, giving the lower limbs of the affected person an appearance similar to the legs of an elephant, that elephantiasis derives its name. This pathology can have two very different origins. The most common is a parasitic disease, present mainly in Africa and Asia: caused by a filiform parasite, it is also called lymphatic filariasis. The other form, elephantiasis nostras verrucosa, is a very exceptional case linked to the obstruction of the lymphatic vessels.

Definition of elephantiasis

Elephantiasis is characterized by swelling of the lower limbs that looks like elephant legs. The oldest traces of this pathology which have been found date back to more than 2000 years BC Thus, a statue of the pharaoh Mentuhotep II was represented with a swollen leg, a characteristic of elephantiasis, which is in fact a symptom a serious infection also called lymphatic filariasis. This parasitic disease, present in Asia and Africa, is totally absent from Europe.

The other form of elephantiasis, referred to as Our warty elephantiasis, which can be found in France, is due to obstruction of the lymphatic vessels, due or not to a bacterial infection. It remains very exceptional.

Causes of elephantiasis

Elephantiasis is an extreme feature of lymphatic filariasis: a disease caused by small parasites, or filaria, that lodge in human blood and tissue, and are transmitted by mosquitoes, their vector. These worms are 90% Wuchereria Bancrofti, the other species being mainly Brugia Malayi et Brugia fears. The larvae are microfilariae, living in the blood. When they become adults, these parasites are found in the lymphatic system, which is all the structures and vessels that play a key role in the immune system. These filaria residing in the lymphatic vessels dilate and obstruct them, causing swelling of one or more limbs. This mainly concerns the lymphatic vessels in the lower part of the body, for example in the groin, genitals and thighs.

Concerning our verrucous elephantiasis, therefore not caused by the parasite, the origin of lymphedemas is linked to an obstruction of the lymphatic vessels, which may or may not be of bacterial origin. Lymphedema would then be linked to a chronic state of inflammation.

Other situations can still cause elephantiasis: diseases called leishmaniasis, repeated streptococcal infections, they can also be consequences of the removal of lymph nodes (often with the aim of preventing the development of cancer), or still be linked to an inherited birth defect.

Diagnostic

A clinical diagnosis should be made if there is a swollen lower limb, or if the swelling is more pronounced on one limb than the other. The first diagnostic step for lymphatic filiarosis is to establish a history of exposure to the parasite in endemic areas. Then laboratory tests can confirm the diagnosis.

• These tests are based on the detection of antibodies.
• A skin biopsy can also help identify microfilariae. 
• There is also a method based on ultrasound, a type of vascular ultrasound that can locate and visualize the movements of the adult parasite.
• Detection techniques such as PCR tests make it possible to demonstrate the presence of the parasite’s DNA, in humans as well as in mosquitoes.
• Lymphoscintigraphy, a technique for exploring lymphatic vessels, has shown that even in the early and clinically asymptomatic stages, lymphatic abnormalities can be detected in the lungs of infected people.
• Immunochromatographic tests are highly sensitive and specific for the diagnosis of W. Bancrofti infection.

Regarding the very rare elephantiasis nostras verrucosa, the diagnosis can be made by the phlebologist. He identifies himself at his clinic.

The people concerned

• 120 million people worldwide are affected, 40 million of whom suffer from severe forms with significant clinical manifestations of lymphatic filariasis: lymphedemas, elephantiasis and hydrocele.
• This disease mainly affects populations in Africa and Asia, and the western Pacific. The pathology is present but not common in the Americas and the eastern Mediterranean, and it is totally absent in Europe.
• Adults, especially between 30 and 40 years old, are more concerned than children, because although this disease often begins in childhood, it is in adults that filariasis becomes important, due to the progressive obstruction. lymphatic vessels.
• Cases of elephantiasis in France can be side effects following the removal of lymph nodes, for example following cancer.

Risk factors

Transmission of the parasite in the community is at increased risk if hygienic conditions are poor.

The most characteristic symptom of elephantiasis is swelling, unilateral or bilateral, of the lower limbs. These swellings are soft and reducible in the early stages, but become hard, or firm to the touch, in old lesions.

In male patients, lymphatic filiariasis may also manifest itself as swelling of the scrotum or hydrocele (a bag filled with fluid in the scrotum). In women, there may be swelling of the vulva, not tender except in cases of acute access.

There may also be oozes, which are smelly.

Other symptoms during the acute phase

• Fever.
• Pain in the infected limb.
• Red and sensitive traces.
• Discomforts.

Symptoms ofour warty elephantiasis are close, with always the presence of a swollen body member, they are furthermore also characterized by warts on the skin.

Several types of therapies exist for the treatment of elephantiasis linked to parasites:

• Drug treatments: ivermectin and suramin, mebendazole and flubendazole, or even diethylcarmazine, and albendazole.
• Surgical treatments: Hydrocele can be treated with surgical procedures, such as excision. An infected limb can also be treated surgically, by drainage or excision procedures.
• Heat treatment: The Chinese have successfully tested a new method in the treatment of lymphedema, which alternates hot and cold.
• Herbal medicine: several herbs have been prescribed for centuries in the treatment of elephantiasis: Vitex negundo L. (roots), Butea monosperma L. (roots and leaves), Ricinus communis L. (sheets), Aegle marmellos (sheets), Canthium mannii (rubiacées), Boerhaavia diffusa L. (whole plant).

Several strategies are in place to treat elephantiasis of non-parasitic cause, which is still very difficult to treat:

• Massages, bandages, compression.
• Skin hygiene.
• Removal of tissue by surgical debridement.
• Ablative carbon dioxide laser, a new technique that has recently been successfully tested.

Drug prevention of filariasis

Vast massive drug administration programs over the past thirteen years have, according to the World Health Organization (WHO), prevented or cured more than 96 million cases. Eliminating this lymphatic filariasis is possible by interrupting the cycle of transmission of the parasite.

• In fact, providing treatment on a large scale to entire communities where parasite infection is present can help stop the spread of infection. This strategy, which is preventive drug therapy, consists of giving a combined dose of two drugs annually to populations at risk.
• Thus, albendazole (400 mg) is given concomitantly with invermectin (150 to 200 mg / kg) or with diethylcarbamazine citrate (6 mg / kg). These drugs, with limited effects on adult parasites, effectively reduce the number of microfilariae in the bloodstream, or parasite larvae. They prevent the spread and development towards mosquitoes. The adult forms of the parasite can remain alive for years.
• In countries where another parasite, called Loa loa, is present, this preventive strategy should preferably even be given twice a year.

Egypt is the first country in the world to have announced the complete eradication of lymphatic filariasis, according to the WHO.

Control of vector mosquitoes

Control of the disease vector, mosquito, can increase elimination efforts, reducing mosquito density, and preventing contact between humans and mosquitoes. Interventions to control malaria, by aerosols and insecticides, have beneficial collateral effects by also reducing the transmission of lymphatic filariasis.

Prevention ofour warty elephantiasis

In terms of elephantiasis unrelated to the parasite, it should be noted, in general, the prevention against obesity, which is one of the risk factors.

En conclusion

It is since 1997 that all these steps have been initiated towards the elimination of lymphatic filariasis as a major public health problem. And in 2000, WHO launched the global program for this eradication, with two components:

• stop the spread of infection (by interrupting transmission).
• relieve the suffering of affected populations (by controlling morbidity), by means of a treatment protocol, including surgery, good hygiene and skin care, in order to avoid bacterial superinfection.