It is so common that about one per cent of the natives of certain villages on the Ivory Coast, West Africa, are subject to it.

As a rule the earliest symptoms in childhood are: more or less persistent headache, particularly frontal, sanguineous and purulent discharge from the nostrils, and the formation of symmetric swellings the size of an almond in the region of the nasal processes of the superior maxilla.

The cartilage does not seem to be involved, and, although it is not so stated, the nasal duct appears to remain intact.
The headache and discharge continue for a year, and the swelling continually increases through life, although the symptoms gradually disappear, the skin not becoming involved, and no pain being present.
It has been noticed in young chimpanzees.

The illustration represents a man of forty who suffered from the disease since puberty.

Pressure on the eyeball had started and the native said he expected that in two years he would lose his sight.