Mondo Description Onchocerciasis is a form of filariasis, caused by the parasitic worm Onchocerca volvulus, transmitted by the black fly. The infection can either be asymptomatic or manifest as an ocular disease (river blindness) with itchy eyes, erythema, photophobia, onchodermatitis or onchocercal skin disease (classified into acute papular, chronic papular, lichenified, atrophic, and depigmentated) and onchocercomas (over bony prominences). Other classic clinical manifestations are ichthyosis-like lesions (''lizard skin'') and ''hanging groin'', which may be associated with lymphadenopathy.

Disease Ontology Description A filariasis that involves parasitic infection caused by the nematode Onchocerca volvulus, which is transmitted to humans through the bite of a blackfly of the genus Simulium. The worms spread throughout the body and, when they die, cause intense itching and a strong immune system response that can destroy nearby tissue. The symptoms include pruritus, dermatitis, blindness, onchocercomata (subcutaneous nodules), and lymphadenopathy.