## 3 Ways to Assess Psoriasis Severity and Therapeutic Strategies for Psoriasis Treatment
### Therapeutic Strategies in the Treatment of Psoriasis  
#### 3.2.1 Topical Treatment  
According to the recommendations of the Polish Society of Dermatology [23] and the standard way of classifying psoriatic lesions (Figure 1), patients presenting a picture of mild disease are qualified for topical treatment of psoriasis. The multitude of patients qualified for topical treatment [18] makes this method an extremely important element of therapeutic success in these patients. In the first stage of topical treatment, the most important thing is proper skin preparation, which will allow drugs to penetrate deep into the emerging skin lesions and increase their effectiveness [23]. Removal of the skin scales covering the psoriatic lesions, which are an obstacle to the penetration of antisporiatic drugs deep into the lesions, is a prerequisite for an effective course of topical treatment [23]. Preparations that soften the keratinized layer of the epidermis [19] and remove the crusts covering the scales include keratolytic preparations (drugs containing urea, salicylic acid, lactic acid, sulfur) [23]. A commonly used agent with proteolytic, keratolytic, penetration-enhancing and epiderm-thinning effects is urea. The results of the study presented by the authors [25] confirmed the above-mentioned actions of urea in monotherapy, as well as in combined therapy, but also proved that its use is safe and associated with mild side effects (mild irritation). Another preparation with a keratolytic effect is salicylic acid. It has the most effective effect on concentrations equal to 5% and higher. The mechanism of action of salicylic acid is to reduce intercellular cohesion and lower the pH of the stratum corneum, which increases the possibility of penetration of therapeutic preparations deep into the skin [25]. The effectiveness of this substance in the treatment of psoriatic skin was confirmed by the authors [26], who conducted a study on a group of patients with scalp psoriasis. The subject of the study was a foam containing 6% salicylic acid, the application of which resulted in complete removal of psoriatic lesions in 60% of the subjects. The same authors confirmed that salicylic acid has many adverse effects (systemic intoxication, central nervous system symptoms, tinnitus, hyperventilation). In their opinion, the validity of its use is still a controversial topic [25]. Emollients are also a group of topical preparations [23]. Their occlusive action minimizes the evaporation of water from the deeper layers of the skin and allows  
Figure 1: Diagram showing how to classify the severity of psoriatic lesions based on [23]. hydration of the stratum corneum [25]. On the other hand, the results of clinical studies presented by the authors [25], which included a total of 111 patients, allowed the thesis that the effectiveness of emollients in monotherapy is limited. However, the Polish Dermatological Society recommends the use of these substances for psoriatic skin [23]. Along with the duration of topical therapy, combination preparations (calcipotriol combined with betamethasone), topical corticosteroids, vitamin D3 analogs and calcineurin inhibitors, as indicated by the authors [18; 23; 27], are included in the treatment of psoriasis. The essential role of glucocorticoids is to neutralize inflammation, have antiproliferative, immunosuppressive, and vasoconstrictive effects [27; 28]. The choice of the appropriate glucocorticoids preparation is related to the level of severity of the skin lesion, its location and the age of the patient [28]. The classifications presented by the authors [29] distinguish topical glucocorticoids by potency. The American classification distinguishes the division into VII groups, of which group I includes preparations with very high potency, and VII with the weakest potency [28; 29]. The European classification lists IV groups of topical corticosteroids, but according to this division, class I includes preparations with the weakest potency, and group IV with the strongest potency [29].