B73.09

Clinical Causes: Transmission occurs through the bite of blackflies (Simulium species) that breed near fast-flowing rivers and streams. The blackfly becomes infected by feeding on individuals already harboring the Onchocerca volvulus larvae. The larvae develop into adult worms within the human body, often forming nodules under the skin. Adults produce microfilariae (larval stage), which migrate through the skin and eyes, causing inflammation and tissue damage.

Key Symptoms: Itching and skin rash, especially in areas where the worms are present. Swelling and inflammation of the eyelids or around the eyes. Eye discomfort, irritation, or redness. Progressive visual impairment or decreased vision. Presence of nodules on the eyelid or around the eye. In severe cases, blindness due to damage to the cornea or other eye structures.

Diagnosis Path: Diagnosis usually involves a combination of clinical examination and laboratory tests. Healthcare providers may look for characteristic skin nodules or eye signs. Microscopic examination of skin snips can detect microfilariae. Imaging techniques or slit-lamp examinations can reveal eye involvement. Blood tests to identify microfilarial antibodies may also support diagnosis. The focus remains on associating eye findings with confirmed onchocerciasis exposure history.

Treatment Protocols: Management typically includes antiparasitic medications such as ivermectin, which effectively reduces microfilarial loads. In cases involving eye damage or eyelid infestation, additional treatments like corticosteroids may be used to control inflammation. Surgical interventions might be necessary to remove nodules or repair damaged tissues. Preventive strategies involve controlling blackfly populations and avoiding exposure in endemic areas. Regular follow-up is essential to monitor for blindness progression or recurrent infections.