The Spectrum of Management for Psoriasis: From the Known to New Alternatives

Abstract

Psoriasis is a chronic, immune-mediated systemic condition characterized by inflammatory changes that may involve the skin and joints. It is relatively common, with a prevalence rate of 2–4% in North America, and a global prevalence rate of up to 11.4%. Years ago, affected patients may have ranged in age from 18–39 to 50–69 due to bimodal distribution. While initially thought to be a dermatologic disease, it is now a recognized multisystem condition with a genetic predisposition. The complex pathophysiology is thought to originate from dysregulation between the innate and adaptive immune systems. T-lymphocytes, dendritic cells, cytokines such as interleukin (IL) 23, IL-17, and tumor necrosis factor (TNF) have all been implicated in and contribute to the inflammatory sequelae. The chronicity and pathogenesis of disease may predispose patients to significant functional impairments, associated comorbidities such as metabolic syndrome and cardiovascular disease, and diminished quality of life. This has prompted novel approaches to management with the introduction of biologics and small molecule therapies that address the underlying immune dysregulation.

There are multiple clinical manifestations including plaque psoriasis, guttate psoriasis, erythrodermic psoriasis, and pustular psoriasis. Among the most common is plaque psoriasis which typically presents as symmetrically distributed, well demarcated, erythematous, scaly plaques or patches that may be pruritic. Common sites of involvement include the extensor surfaces of the elbows, knees, the trunk, gluteal cleft, and scalp. Guttate psoriasis is typically preceded by upper respiratory infections and represents approximately 2% of all cases of psoriasis. It involves several small (<1 cm) confetti-like papules and plaques. A severe, although uncommon form is erythrodermic psoriasis which results in widely distributed erythema, scales and exfoliation of a large surface area of the skin. Due to the widespread loss of the epidermal, dermal barrier and associated risk of fluid loss, electrolyte disturbances and infection, it is considered a dermatologic emergency. Pustular psoriasis is also an uncommon, potentially severe, clinical variant, with possible complications secondary to acute widespread erythema and development of multiple pustules.