Psoriasis is a complex immune-mediated disease that affects approximately 120 million people globally and requires chronic management.1 The condition manifests itself in the skin, joints, or both, and exhibits associated comorbidities that increase risk for early death, including metabolic syndrome, cardiovascular disease, psoriatic arthritis, depression, anxiety, nonalcoholic fatty liver disease, Crohn’s disease, and lymphoma.2
Physicians should encourage lifestyle changes to reduce modifiable cardiovascular risk factors, such as smoking, which has been shown to independently increase risk of onset and exacerbation of psoriasis. Excessive alcohol intake has been reported in up to one-third of patients with psoriasis, likely due to psychologic distress. Excess alcohol ingestion is also a risk factor for cardiovascular disease.3 As emerging research illustrates its increasing complexity, psoriasis is now considered a systemic inflammatory disorder.2
Clinically, there are 5 types of psoriasis: plaque psoriasis, guttate or eruptive psoriasis, inverse psoriasis, pustular psoriasis, and erythrodermic psoriasis. Plaque psoriasis is the most common form, with monomorphic, well-demarcated erythematous plaques under a silvery scale, typically on the scalp and extensor surfaces. Guttate psoriasis exhibits tear-drop shaped lesions with scale. Inverse psoriasis is found in the intertriginous or flexural areas. Pustular psoriasis can present as either palmoplantar pustulosis or as the serious generalized pustular psoriasis. Any form can evolve into erythrodermic psoriasis, a rare and serious complication of the disease with significant risk of mortality. Psoriasis can affect the skin, nails, scalp, and joints to different degrees in each patient.2,4
The prevalence of psoriasis within certain populations ranges from less than 1% to more than 10%, depending on ethnic and geographic factors, with a 2% prevalence rate in Europe and North America.5 Family studies have shown a genetic predisposition for the disease, with the literature illustrating certain susceptibility alleles in immune-related genes.6,7 Dysregulation between the innate and adaptive immune systems, tumor necrosis factor (TNF)-α, and the interleukin (IL)-23-T helper cell 17 (Th17) axis, among other immune reactions in the cells of the skin, have all been shown to be involved in the pathogenesis of psoriasis.2,8
Management varies according to severity and effect on quality of life and should be tailored to each individual patient. There are many therapeutic options available, ranging from topical agents, to phototherapy and systemic and biologic agents.1,2
This article discusses established therapies for psoriasis and their indications for use, as well as emerging treatments that hold promise for the future.
Meet the patient
A 55-year-old postmenopausal woman with a past medical history of hypertension, dyslipidemia, non-insulin-dependent diabetes, and a 30-year history of psoriasis presents to a dermatology clinic with worsening symptoms and spread of her disease that were causing her physical and mental distress. She had been using various topical medications with only partial control. She had tried photochemotherapy in the form of psoralen plus ultraviolet (UV)-A (PUVA) treatments several years ago, but could not maintain weekly treatments because the 40-mile drive to the clinic was too inconvenient. In the last 2 years, she had 1 basal cell carcinoma and 1 squamous cell carcinoma excised. Her medications include metformin and simvastatin. She smoked 1 pack per day (ppd) of cigarettes in her 20s and 30s, but cut down to one-half ppd after being informed that smoking may aggravate her psoriasis. She drinks approximately 3 glasses of wine per night and says they help her sleep.
Her physical examination reveals an obese woman with fair skin and psoriasis involving 25% of her body surface area (BSA), when it had previously involved less than 10% of her BSA. Erythematous, tender patches and plaques with silvery scales are visible on the trunk, lower back, and upper and lower extremities. Thick plaques with silvery white scale are found throughout the scalp. Her palms and the plantar aspects of her feet also exhibit mild erythematous patches. There is no onychodystrophy, and no signs or symptoms of psoriatic arthritis are evident.