Trophic lesions of the lower limbs in black patients

Abstract

The legs of black people living in tropical countries are
often the seat of cutaneous lesions : from multiple scars
due to minor trauma in childhood to less common but
more serious lesions. Mycetomas with involvement of the
skin, the muscles and the bone may lead to amputations.
An erythema nodosum leprosum is sometimes a reaction
to the treatment of leprosy. Filariasis may cause skin
lesions. Dracontiasis, or Guinea worm, (Dracunculus
medinensis) produces a vesicle on the skin in which the
spaghetti-like worm gradually appears – it is then
extracted by the “indigenous method” which consists in
twirling it slowly and progressively daily around a small
stick until it is removed. In central Africa a Loa Loa
infection causes pruritus and transitory migratory areas
of oedema mostly on the face and arms but more rarely
on the legs when it is associated with cardiac
complications. Onchocerciasis, is transmitted through
the bite of black-flies (Simulium). It produces
subcutaneous nodules (which contain a dense mass of
connective tissue with encapsulated adults worms) and a
severe pruritic skin rash resulting in a lichenification of
the skin and a depigmentation of the skin in the pretibial
region; but the major risk is the eye lesions (retinitis and
choroiditis) which lead to permanent blindness. Finally,
the most spectacular lesions of the legs are due to
lymphatic filariasis (Wuchereria bancrofti), transmitted
through mosquito bites, which provoke a lymphadenitis
with lymphangitis, a chyluria and, particularly, an
elephantiasis. The diagnosis is confirmed when the
microfilariae are found in the blood drawn at night.
Ivermectin is an effective treatment of the filariasis, but
the elephantiasis requires prolonged firm bandaging and,
often, surgical excision.