Resolving Hyperkeratotic Psoriasis: Mechanisms of Action and Additive Effects of Fixed-Combination Halobetasol Propionate and Tazarotene

Hyperkeratotic plaque psoriasis represents a distinct morphological variant that is difficult to treat with topical therapies because thick lesions may impede the penetration of active ingredients. The immunoregulatory mechanisms of topical corticosteroids (TCSs) and tazarotene (TAZ) may contribute to combating hyperkeratosis and long-term remittance of psoriasis. A fixed-combination lotion containing the potent-to-superpotent TCS halobetasol propionate (HP, 0.01%) and TAZ (0.045%), indicated for the topical treatment of plaque psoriasis in adults, was developed to harness the therapeutic benefits of each active ingredient while minimizing their safety concerns. This review describes data supporting the efficacy of halobetasol propionate (0.01%) and tazarotene (0.045%) lotion (HP/TAZ) and remittive effect after treatment cessation in patients with hyperkeratotic plaques. Pivotal trials demonstrate the superior efficacy and safety of HP/TAZ over each active ingredient alone. Furthermore, we summarize a recent clinical study, which showed that HP/TAZ reduces lesional levels of tumor necrosis factor alpha and interleukin 17A, critical proinflammatory cytokines involved in keratinocyte hyperproliferation and psoriasis pathogenesis. This review suggests that HP/TAZ is a valuable option for the topical treatment of severe hyperkeratotic plaques through its additive mechanisms targeting inflammation and keratinocyte regulation.