A variety of infections and disorders can cause feet to itch. Sweaty feet, synthetic-fabric socks, tight shoes and shoes made of occlusive materials can make the condition worse. Determining the cause of the itch is imperative to correctly treat the condition.
Dermatophytes
Dermatophytes are a common group of fungi that cause athlete's foot, ringworm, jock itch and a variety of other skin diseases. Dermatophytes live on skin, in soil, on objects and on pets. Some species remain viable for up to 15 months without a host. Absolute Astronomy reports that the main genera of dermatophytes that infect humans are mircorsporum, epidermophyton and trichophyton with about 40 species in these genera. Tinea pedis, or athlete's foot, is most often caused by Trichophyton (T.) rubrum, T. interdigitale or Epidermophyton floccosum. Onychomycosis is a dermatophyte infection of a finger- or toe-nail and nail bed. Athlete's foot typically occurs in moist areas, particularly between the toes, most often between the fourth and fifth toes, though it can occur on the rest of the foot as well. The infection causes a red, itchy rash. Scaling, or flaking, skin is common and, as the skin breaks down, tears and fissures are common, allowing for secondary bacterial infections.
Dyshidrosis
Dyshidrosis, which is also known as "dyshidrotic eczema," and "pompholyx," is a condition in which skin becomes inflamed, allowing fluid to build up between skin cells, creating a sponge-like feeling in tissues. It creates small blisters on skin, causes fissures to develop on the hands and feet, includes pain and causes intense itching. Mayo Clinic that the blisters generally last for about three weeks. As of 2010, the underlying cause of dyshidrosis is not known, however it often accompanies the allergic symptoms of hay fever and asthma. DermaNet NZ reports that dyshidrosis may be caused by abnormal sweating.
Chilblains
Chiblains is a localized from of cutaneous vasculitis, an inflammation of the blood vessels in the skin as a reaction to temperature variations. Chilblains typically appear on the hands and feet. It produces small, tender, red or purple, bumps on skin, along with itching. When skin is exposed to cold temperatures, blood vessels in the exposed area constrict. When the warm up is sudden, blood can seep from dilating blood vessels into surrounding tissue. Pressure on the skin, such as that imposed by wearing tight shoes, can aggravate the condition.
Hookworm
Hookworms are parasitic nematodes, or roundworms, that live in soil and can infect animals and humans. The two species of hookworm that typically infect humans are Ancylostoma duodenale and Necator americanus. People pick up the parasite by walking barefoot where the larvae are present. The larvae can enter through cracks in the bottom of the foot, through hair follicles, or even through healthy, intact skin. Within 30 minutes of infection, a tingling feeling can be felt where the worm larvae entered the feet. The larvae may lay dormant for weeks or months, or begin to migrate immediately. DermaNet NZ reports that the infection is also called "creeping eruption" because the larvae, as it makes its way beneath skin, causes red, itchy tracks.
