Itchy foot soles can be caused by a number of factors such as allergies, insect bites or infection, according to Healthgrades.com. Other common causes are diseases such as eczema or chicken pox.
Another common causes of foot itch, according to Healthgrades.com, is a fungal infection, such as athlete's foot. Several insects, including pinworms and the itch mite Sarcoptes scabiei, are known to cause intense itching on the soles of one's feet. In general, most causes of itchy feet are mild and don't require medical attention. However, if one experiences a sudden onset of intense itching in the feet, it may be the sign of a more serious condition such as anaphylaxis, which is a life-threatening allergic reaction to food. If anaphylaxis is suspected, one should seek emergency medical help right away.