The black disease of Arabia, Sowda-onchocerciasis. New findings.

Sowda, the localized asymmetrical lesion of onchocerciasis endemic in Yemen and Southern Saudi Arabia, is characterized by hyperpigmented lichenified papular lesions on one leg with intense pruritus. There is enlargement of femoral and inguinal lymph glands. In our study, even the long standing cases do not show elephantiasis of the leg or genitalia. Microfilaria appeared to be scarce and adult worms could not be detected clinically, as well as by ultrasonography (except in one case). There was no significant lymphatic obstruction; such cases were studied by contrast lymphangiography and isotope lymphangiography.