Symptoms
The symptoms of onchocerciasis are not caused directly
by the worm itself but by an inflammatory reaction to the death of microfilaria
in the skin and eyes. The microfilariae that are not ingested by the
blackflies may live up to two years. In a heavily infected person there
can be 100,000 or more microfilariae dying every day.The most common
symptoms are skin rashes and severe itching. Over the years the inflammation
of the skin leads to its degeneration, with changes in pigmentation
and elasticity. The depigmentation, usually in the pretibial area, develops
into white spots, which is called "leopard skin." Due to the
reaction elastic fibers in the skin are also destroyed, resulting in
a wrinkled, cigarette paper appearance, which can, if atrophy of the
skin continues, lead to a situation in which the groin prolapses, called
"hanging groin." Through repeated infections over the years,
the tiny worms migrate along the skin and eventually reach the eyes.
The immune reaction of the body to the microfilaria often leads to blindness
and serious skin alterations. In the most affected communities, over
50% of the population can be expected to go blind before their demise.
