According to the World Health Organization, psoriasis, a common chronic autoimmune disorder of the skin, causing redness, irritation and scaly lesions, affects up to five percent of the world’s population.
Approximately 12 million people in the United States have psoriasis; of these, an estimated 7.5 million have been diagnosed with the skin disease and an estimated 50‑60% of diagnosed patients are actively being treated. Of those patients in active treatment, an estimated 50-60% of these patients have moderate to severe pruritus. In a recent survey of 5,604 psoriasis patients, over 90% reported pruritus as a significantly bothersome symptom.
The severity of the pruritus in psoriasis patients does not always correlate with the severity and number of skin lesions, suggesting that pruritus and skin inflammatory disease may be somewhat independent of each other in patients with psoriasis. Mild to moderate psoriasis is typically treated with topical therapies such as corticosteroids or vitamin D analogs. Moderate to severe psoriasis may be treated with topical therapies, systemic immunosuppressive or immunomodulatory drugs, or phototherapy.
While all of these therapies can help reduce the skin irritation and plaques in patients with psoriasis, and may also reduce pruritus to some degree, they may not adequately resolve the pruritus associated with psoriasis.