A 40-year-old man in rural Côte d'Ivoire presents with progressive bilateral visual impairment. Slit-lamp examination reveals 'snowflake' corneal opac...

Question

A 40-year-old man in rural Côte d'Ivoire presents with progressive bilateral visual impairment. Slit-lamp examination reveals 'snowflake' corneal opacities and sclerosing keratitis. He has multiple firm subcutaneous nodules (onchocercomata) on the iliac crests. What is the underlying pathological mechanism of the keratitis?

Accepted Answer

Inflammatory response to dying microfilariae in the cornea

Answer

Direct invasion of the cornea by adult Onchocerca volvulus worms

Answer

Allergic reaction to Simulium blackfly saliva

Answer

Nutritional vitamin A deficiency

Answer

Secondary bacterial keratitis

uk-dtmh MCQ (SBA): Onchocercal Keratitis