The “culprit” that causes foot odor is a fungus called Tinea albicans, or commonly known as athlete’s foot fungus, which decomposes skin metabolites and produces an unpleasant odor. Foot in sweaty conditions, bacteria or fungi multiply and decompose keratin, plus sweat in the urea, lactic acid, and issued a bad smell. If the shoes are not breathable, the air does not circulate, the odor will accumulate more and more thick, the stench is unusually strong. The cause of foot odor is formed by the following reasons together: 1, humid environment: children’s feet sweat glands secrete a lot, when the moisture content is high is very favorable to the breeding of bacteria and mold. 2, stuffy and confined space: When shoes are worn very closely, ventilation and air permeability is not good, in addition to the increase in water, the PH value of the skin surface will change, and will release carbon dioxide gas, such an environment is most suitable for the growth of certain bacteria on the soles of the feet. 3, the reproduction of bacteria: after sweating the humidity and pH value of the shoe to provide a suitable environment for the growth of bacteria, coupled with the skin necrosis of the keratin layer to bring bacteria enough nutrition, so that bacteria can multiply to decompose keratin and mixed with sweat in the urea, lactic acid to produce an unpleasant odor. 4, too thick old keratin: too thick old keratin, infiltrated by sweat, will become a source of nutrients needed by bacteria and mold, promote the proliferation of bacteria, mold reproduction, worsening the formation of foot odor. When children have smelly feet, the above-mentioned causes should be removed, and you can also choose medication and dietary regimen to improve the problem of smelly feet.