The composition of the skin on the feet is different from the skin elsewhere on the body, as it is adapted to the constant mechanical stresses it experiences on a daily basis. In addition, the feet and toenails are susceptible to fungal infections. In this thesis, we review the contrasting characteristics of plantar and non-plantar skin composition, the pathophysiology of hyperhidrosis (excessive sweating), which occurs as a primary process of autonomic neuronal dysfunction, and factors such as friction and excessive mechanical stress that contribute to the formation of hard skin. We have also looked at the mechanism of action of dermatophytes that cause fungal foot infections in the dark and moist environment of footwear. We were interested in which cosmetic foot care products are available on the Slovenian market and whether they contain cosmetically active ingredients that are safe to use. The products reviewed were classified into three groups according to their purpose: hyperhidrosis, hyperkeratosis and fungal infections. The hyperhidrosis group, which accounts for 21% of the market, is dominated by cosmetic products in spray form (4 products) and three key ingredients: tea tree essential oil, aluminium chlorohydrate and talc, which have been shown to reduce perspiration or absorb sweat. Based on the literature reviewed, we found that talc, which is also used in infant products at concentrations up to 99.9%, is the safest ingredient, while tea tree essential oil is the least safe, as it is difficult to control its chemical composition, which varies depending on the part of the plant, the time and the method of extraction. Products for the care of hard skin on the feet account for 66% of the market, most of them in the form of creams (20 cosmetic products), as this form of cosmetic products is the most effective in moisturising the skin. We looked at the safety aspects related to urea, known for its skin softening properties, and salicylic acid, a keratolytic known for its ability to remove dead cells of the stratum corneum. We have found that urea is safer to use because, as it is the end product of protein metabolism in mammals and the main nitrogenous compound of urine, it is naturally present in the body. For fungal infections (13% of products on the market), we reviewed the safety of hydrogen peroxide due to its proven antimicrobial properties. It is classified as a skin and eye irritant, so its use in cosmetic products is limited to extremely low concentrations, especially in non-rinse-off products (up to 4% in sprays). Based on our findings, we have highlighted the most suitable products for use. We concluded that the products under consideration contain fragrances and essential oils that are potential allergic reactors according to EU Regulation 1223/2019 on cosmetic products. When choosing products, we recommend that consumers ask whether they are susceptible to allergies and make a purchase decision based on this information.
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