Gummata are growths of pink, fleshy tissue that contain syphilis bacteria. They may appear as nodules or ulcers or become masses that are like tumors. Gummata are rare and may be up to 0.5 in. (1 cm) in size. Common sites of gummata include the:
Skin, where they cause shallow open sores that heal slowly.
Mucous membranes. These gummas may become cancerous.
Bones, where they cause destruction of bones and pain that is especially severe at night.
Eyes, resulting in visual impairment that may lead to blindness.