## 5 Substances, Standards, Methods--New Trends in Psoriatic Skin Care
### Keratolytics and exfoliating Substances  
According to the authors [25, 69], in topical therapy of psoriatic skin, it is crucial to properly prepare the affected areas to increase the effectiveness of the preparations used. For this purpose, exfoliating substances such as salicylic acid, lactic acid or urea are used, which facilitate the removal of scales and improve the penetration of drugs, including glucocorticoids. The use of alpha-hydroxy acids (AHAs), beta-hydroxy acids (BHAs) and polyhydroxy acids (PHAs) facilitates the removal of keratinized epidermis by destroying protein bonds between corneocytes [69]. Salicylic acid, the best-known BHA, is widely used in the initial stages of psoriasis treatment for its exfoliating and \begin{table}
\begin{tabular}{p{142.3 pt} p{142.3 pt} p{142.3 pt}} \hline
**Emollients** & **Substance** & **Effects** \\ \hline Basic emollients & Vaseline, paraffin & They maintain the integrity of the skin barrier, resulting in a reduction in transepidermal water loss. \\ \hline Lipid emollients & Linoleic acid, ceramides & They form a tight lipid barrier, thereby reducing transepidermal water loss and preventing the penetration of pathogenic microorganisms into deeper layers of the skin. \\ \hline Occlusive emollients & Beeswax, lanolin, and mineral oils & Form an occlusive layer that reduces transepidermal water loss. \\ \hline Emollients “plus” & Enriched embilient: celastrol & They exhibit additional immunomodulatory, antipruritic, moisturizing, anti-inflammatory, embilient, and reepithelialization-accelerating effects \\ \hline \end{tabular}
\end{table} 
Table 5: Classification of embilients based on [25, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68]. anti-inflammatory properties. It also enhances the penetration of topical agents, such as corticosteroids, and reduces pruritus [25; 69]. Its mechanism and risks have been discussed in Section 3.2.1. Clinical studies [70] confirm that salicylic acid is an effective treatment in the initial stages of plaque psoriasis therapy and as a regular adjunct to other methods used. Its efficacy is greatest in thick and scalp psoriatic plaques [25; 70]. The authors [61] point out that extreme caution should be exercised when using salicylic acid, as its inappropriate extensive use leads to the salicism mentioned earlier. Glycolic and lactic acids, which belong to the AHA group of acids indicated by the authors [13; 69] for psoriatic skin care, exhibit exfoliating properties, as well as moisturizing and stimulating collagen and glycosaminoglycan synthesis. AHA penetrate deep into the epidermis, inducing an increase in the frequency of replacement of the stratum comeum, resulting in exfoliation of its outer layers while maintaining the normal skin barrier [25; 69]. Glycolic acid and lactic acid have the effect of reducing the cohesion of corneocytes by increasing the distance between them due to increased water retention in the stratum corneum [25]. PHA, on the other hand, have antioxidant and moisturizing properties, which have a protective effect on psoriatic skin whose skin barrier is disrupted. The use of AHA and PHA together with topical corticosteroids provides a synergistic effect and counteracts skin atrophy that can be caused by steroid therapy [25; 69; 71]. A double-blind clinical trial was conducted to evaluate the efficacy of AHA in patients with scalp psoriasis [71]. The effects of 5% glycolic acid and 5% lactic acid in combination with topical corticosteroids were analyzed. Three different preparations were used in 20 patients with scalp psoriasis: a lotion with 5% glycolic acid and 5% lactic acid at pH 3.5, a placebo lotion (containing 40% ethanol, 20% propylene glycol and 40% deionized water), and 0.1% betamethasone. Patients applied two different formulations to each side of the head twice a day without a bandage for 8 weeks.