A mallet toe can be described as a deformity of the distal interphalangeal joint (the last toe joint), which bends downwards.
The skin near the toenail tip can develop a painful corn that can eventually result in an ulcer. These can be extremely painful. The toe can become red and swollen.
Because the second toe is typically the longest, it is the most likely to be affected by mallet toe.
It can occur from injuring a toe, poor footwear, bone or muscle imbalances or arthritis.