Lymphadenitis in Sowda

Sowda is a form of onchocerciasis in Yemen characterized by unilateral dermatitis of one limb, with enlargement of the regional lymph nodes. Previous pathologic studies of lymph nodes from cases of Sowda describe only follicular hyperplasia without microfilariae in the lymph nodes. This contrasts with African onchocerciasis, where the lymph nodes tend to be atrophic and microfilariae are usually present. In the present report, a case of Sowda with microfilariae in the lymph nodes is described and the implications of this finding are discussed.