*2.3.1 Corticosteroids*

Corticosteroids play a key role in the management of psoriasis. In this context, their mechanism of action involves the reduction of skin redness and the expression of anti-inflammatory mediators, as well as achieving an improvement and/or clearance of psoriatic plaques (**Figure 4**) [87]. These effects are exerted via intracellular corticosteroid receptors, which regulate gene transcription, including several that code for pro-inflammatory mediators. Topical corticosteroids are classified based on their skin vasoconstrictive activity, ranging in strength (potency): (a) super potent/ ultrahigh (e.g., clobetasol propionate 0.05%); (b) high (e.g., mometasone furoate 0.1%); (c) moderate (medium) (e.g., betamethasone valerate 0.1%) [43, 86] and (d) low (e.g., hydrocortisone 1.0%) [43]. Choosing a corticosteroid with appropriate

#### **Figure 4.**

*The choice of management strategy for psoriasis is driven by the skin's dryness and itchiness; inflammation and redness; scaliness and thickness [6, 35, 45, 86, 87, 91, 99].*

potency plus the appropriate topical formulation should be based on the disease severity and area affected, and the patient's preference and age [88]. Lower potency corticosteroids such as hydrocortisone should be used on the face, intertriginous areas, and areas that are susceptible to steroid atrophy (e.g., forearms) [88, 89]. In adults, higher potency corticosteroids such as clobetasone butyrate and mometasone furoate are generally recommended as initial therapy [86, 88, 90]. Areas with thick, chronic plaques often require management with ultrahigh-potency corticosteroids. In numerous randomised clinical trials [4, 91–94], different potency topical corticosteroids were effective and safe at 2 to 4 weeks in the management of mild to severe plaque psoriasis. Evidence on the efficacy of topical corticosteroids for the management of psoriasis varies greatly due to the differences in study designs, patient populations, corticosteroid class and concentration, adverse effects and outcomes [86].
