onchocerciasis

“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.”