Itch: an under‐recognized problem in psoriasis

Abstract

Psoriasis has historically been considered a nonpruritic dermatosis, in contrast with atopic dermatitis. Thus, itch has often been underappreciated and overlooked in psoriasis. However, increasing evidence over the past decade has shown that itch can be one of the most prevalent and burdensome symptoms associated with psoriasis, affecting almost every patient to some degree. Itch can involve the entire body, although it predominantly affects the legs, hands, back, body and especially the scalp. Uncontrolled itch can significantly impact all aspects of the well‐being and quality of life of the patient. While there has been some progress in trying to better understand the pathophysiology of itch in psoriasis, more research effort and interest are needed. This under‐recognition of itch in psoriasis is clearly reflected in the dearth of treatment options targeting itch despite significant advancement in treating the lesions themselves. Recently, however, clinical studies have begun to include itch as a study outcome. The resulting data have demonstrated concomitant antipruritic benefits and improved Psoriasis Area and Severity Index (PASI) scores with mainstay treatments for psoriasis, such as topical corticosteroids and vitamin D analogs, phototherapies, and various systemics and biologics. This article takes a closer look at this debilitating symptom, reviewing the available epidemiology data for psoriatic itch, presenting the current understanding of psoriatic itch pathophysiology and highlighting important clinical data for various treatment options for itch. Practical considerations for increasing the recognition of itch as well as improving its management in psoriasis are also provided.

Fixed‐dose combination calcipotriol/betamethasone dipropionate foam provides a rapid onset of action, effective itch relief and improves patient quality of life

“…[14][15][16][17][18] Despite this, and the numerous therapeutic options available that target psoriatic lesions, there is a distinct lack of options for managing itch as a symptom. 5 This may be attributed to the fact that the exact pathophysiology of itch in psoriasis is not fully understood, as it involves complex interactions between skin cells, immune cells, secreted factors and cutaneous neural networks. Research suggests an increase in certain itch-related substances and their receptors, such as nerve growth factor and substance P, and a decrease in itch/pain modulating substances, such as neuropeptide Y, may be associated with itch in psoriasis.…”

“…Cytokines released from immune cells, such as IL-17A, IL-23A and IL-31, may also be key itch modulators, although this has yet to be confirmed. 5,29 Cal/BD foam has demonstrated effective itch relief and improved itch-related sleep loss. 28 Although its antipruritic method of action is not fully understood, 5 it appears the topical combination of vitamin D and steroid improves barrier function and may attenuate immune function by inhibiting the cascade of key 'itch cytokines' noted above.…”

“…[1][2][3] The presence of these plaques, in addition to associated symptoms like itch, scaling and redness, has a significant negative impact on patients' health-related quality of life (HRQoL), reducing physical, psychological and social wellbeing. [4][5][6] Despite often being overlooked in the clinical setting, the debilitating effect of psoriasis on HRQoL should not be underestimated. The Global Burden of Disease project ranked skin and subcutaneous disorders, including psoriasis, as the 4 th leading cause of non-fatal disease burden, 7,8 while patients with psoriasis have reported a similar deterioration in HRQoL as patients with other serious chronic diseases, including cancer and cardiovascular diseases.…”

“…Psoriasis vulgaris (chronic plaque psoriasis) is the most common psoriasis subtype and is characterised by scaly erythematous plaques on the skin 1–3 . The presence of these plaques, in addition to associated symptoms like itch, scaling and redness, has a significant negative impact on patients’ health‐related quality of life (HRQoL), reducing physical, psychological and social well‐being 4–6 . Despite often being overlooked in the clinical setting, the debilitating effect of psoriasis on HRQoL should not be underestimated.…”

Inhibition of M/Kv7 Currents Contributes to Chloroquine-Induced Itch in Mice

“…Itch, also known as pruritus, is an uncomfortable everyday experience that evokes a desire to scratch ( Dong and Dong, 2018 ). Itch is commonly caused by chemical pruritogens ( Dong and Dong, 2018 ); meanwhile, itch is also a prominent symptom of many diseases, such as dry skin ( Pereira and Ständer, 2018 ), psoriasis ( Elewski et al, 2019 ), and atopic/allergic dermatitis ( Bieber, 2008 ), as well as patients with system disease such as chronic cholestatic liver disease ( Carey et al, 2015 ) and renal disease ( Simonsen et al, 2017 ). Understanding the neural basis of itch at the molecular, cellular, and circuit levels can identify new therapeutic targets to treat this devastating symptom ( Meixiong and Dong, 2017 ).…”