Usually the problem is recurrence. The anti-fungal creams may work, but the fungus comes back. The key is prevention and preventing fungus from growing is the first step. Fungus like damp, warm environments. Minimizing moisture is key. If you have sweaty feet, use an antiperspirant spray, soak in Burrows® Soaks, 1:40 dilution, for 20 minutes twice a day and/or use foot powder with tannic acid or talcum powder. Another way to decrease moisture is to soak in cider vinegar for 45 to 60 minutes once a day - this creates an inhospitable environment for the fungus, it also dries out the skin (watch for cracks and fissures).
Let the shoes dry completely after use, pull out the insoles and use an anti-fungal powder in the shoes. Rotate shoes daily, try to avoid wearing the same pair repeatedly. You may want to use an anti-fungal soap
The shower should be cleaned with bleach once a week, towels and socks should be washed in hot water and shoe liners should probably be replaced in all shoes.
Tea tree oil
may help treat the fungus, prevent recurrence and can relieve itching and redness. A topical steroid (hydrocortisone 1% at the drug store) can be used when itching and redness are severe. Extended use (more than 2 -4 weeks) is not recommended.
Two to four weeks of the above preventative measures in association with twice daily use of an anti-fungal cream (Lamisil AT is one of the best) should help. If no improvement or if there is worsening, make an appointment with your doctor. More information on foot fungus