Review of the composition and safety of cosmetics foot care products available at Slovenian market

Sestava kože stopal se razlikuje od kože drugod po telesu, saj je prilagojena stalnim mehanskim obremenitvam, ki jih vsakodnevno doživlja. Poleg tega so stopala in nohti na nogah dovzetni predvsem za glivične okužbe. V nalogi smo pregledali značilnosti plantarne in neplantarne sestave kože, patofiziologijo hiperhidroze (prekomernega potenja), ki se pojavi kot primarni proces avtonomne nevronske disfunkcije, in dejavnike, kot so drgnenje in prekomerna mehanska obremenitev, ki prispevajo k nastanku trde kože. Predstavili smo tudi mehanizem delovanja dermatofitov, ki v temnem in vlažnem okolju obutve povzročajo nastanek glivičnih okužb stopal. Zanimalo nas je, kateri kozmetični izdelki (KI) za nego stopal pri teh stanjih so dostopni na slovenskem trgu in ali vsebujejo kozmetično aktivne sestavine, ki so varne za uporabo. 56 pregledanih izdelkov smo razvrstili v tri skupine glede na namen: hiperhidroza, hiperkeratoza in glivične okužbe. V skupini hiperhidroze, ki zavzema 21 % pregledanih izdelkov, prevladujejo KI v obliki spreja (4 izdelki) in tri ključne sestavine: eterično olje čajevca, aluminijev klorohidrat in smukec, ki dokazano zmanjšujejo potenje oziroma absorbirajo pot. Na podlagi pregledane literature smo ugotovili, da je najbolj varna sestavina smukec, ki se uporablja tudi v izdelkih za dojenčke v koncentraciji do 99,9 %. Najmanj varno pa je eterično olje čajevca, saj je težko nadzorovati njegovo kemijsko sestavo, ki se spreminja glede na del rastline, čas in način ekstrakcije. Izdelki za nego trde kože na stopalih zavzemajo 66 % pregledanih izdelkov. Največ jih je v obliki kreme (20 KI), saj je ta oblika KI najbolj učinkovita pri vlaženju kože. Preučili smo varnostne vidike, povezane s sečnino, ki je znana po svojih lastnostih mehčanja kože, in salicilno kislino, keratolitikom, znanim po svoji sposobnosti odstranjevanja odmrlih celic rožene plasti povrhnjice. Ugotovili smo, da je senčnina bolj varna za uporabo, saj je kot končni produkt presnove beljakovin pri sesalcih in glavna dušikova spojina urina tudi naravno prisotna v telesu. Pri glivičnih okužbah (13 % izdelkov na trgu) smo pregledali varnost vodikovega peroksida zaradi dokazanih protimikrobnih lastnosti. Nahajal se je v 1 KI, in sicer v obliki spreja. Klasificiran je kot dražilna snov za kožo in oči, zato je njegova uporaba v KI omejena z izjemno nizkimi koncentracijami, predvsem v izdelkih, ki se ne izpirajo (do 4 % v sprejih). Na podlagi naših ugotovitev smo izpostavili najprimernejše izdelke za uporabo. Zaključili smo, da obravnavani izdelki vsebujejo dišave in eterična olja, ki so možni povzročitelji alergijskih reakcij v skladu z Uredbo EU 1223/2019 o kozmetičnih izdelkih. Pri izbiri izdelkov potrošnikom priporočamo, da se pozanimajo, ali so dovzetni za alergije in se na podlagi te informacije odločijo za nakup.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