The cause of curly toes is generally a rotation of the little toe towards the toe next to it. Often called a curly toe, this condition is the combination of a hammertoe deformity, and an actual inward rotation of the toe.The result of this abnormal toe position is usually a very painful corn that forms due to the pressure from the shoe on the toe, where the toe bone is now prominent due to the toe rotation.
The little toe is not the only toe that can curl inward. This can also be seen in the other smaller toes, although the fourth toe (the one next to the little toe) is the primary toe outside of the little toe to develop this. However, this toe does not tend to develop the same sort of painful corn as the little toe, due to the unique position of the little toe on the outside of the foot.