Subungual Exostosis
This is one of the more common bony lesions of the foot. It is a benign tumor of bone and cartilage. It is generally found underneath the toenail and may press upwards resulting in deformity of the nail plate and/ or soft tissues. In severe lesions, the overlying tissues may ulcerate and become infected. This lesion responds well to surgical excision and rarely reoccurs.

Symptoms
- Deformity and separation of the nail plate, expansion of the soft tissues
 - Direct pressure on the nail may be painful
 - Aggravated by wearing tight shoes.
 - There may be signs of ulceration and infection.
 
Causes
- Cause is unknown, but believed to be trauma
 
What you can do
- Consult a podiatrist or physician
 - Avoid tight fitting foot wear
 - If an infection develops soak the foot in a basin of warm water two or three times a day. Contact your podiatrist or physician immediately.
 - Abnormal growths and infections require prompt professional attention.
 
What the doctor may do
- Take x-rays or perform other imaging to establish a correct diagnosis.
 - If the toenail is causing problems, it may be removed
 - Treat any infection present with antibiotics
 - Surgically remove the exostosis
 - Completely remove a deformed toenail so it will not grow back.
 
Other conditions resembling a Subungual Exostosis
- Other, more serious, bone tumors may resemble an exostosis.
 - Evaluation by a trained practitioner is essential
 - An infected ingrown toenail may resemble an ulceration from an exostosis
 - Chronic in-growing nails can cause deformity of the nail plate and/or surrounding soft tissues.
 
