Psoriasis and Pruritus: Characteristics and Clinical Significance

Pruritus is a significant symptom of psoriasis that affects 60-90% of patients, though it is often under-recognized in clinical practice. 1, 2

Prevalence and Characteristics of Pruritus in Psoriasis

Pruritus (itching) is present in the majority (60-90%) of patients with psoriasis, making it one of the most common symptoms of the disease 1
The intensity of pruritus in psoriasis can range from mild to severe, with most patients experiencing moderate intensity on a daily basis 3
Pruritus in psoriasis can significantly impact quality of life and is often considered by patients to be the most bothersome symptom of their disease 1
Patients with pruritus show greater impairment of health-related quality of life compared to those without pruritus 1

Psoriasis classically presents with well-demarcated, erythematous plaques with silvery scale, commonly involving the scalp, elbows, knees, and presacral region 2
The American Academy of Dermatology recommends that an itch severity assessment be performed for patients whose psoriasis causes significant pruritus 2
The most commonly used tools for assessing pruritus intensity are the visual analog scale (VAS) and numeric rating scale (NRS) 2
A change of 3-4 points on these scales is considered clinically significant 2

Different clinical phenotypes of psoriasis may present with varying degrees of pruritus 2
Plaque psoriasis (psoriasis vulgaris) is the most common form and is frequently associated with pruritus 2
Inverse psoriasis, which affects intertriginous areas such as the axillary, genital, perineal, intergluteal, and inframammary areas, may present with erythematous plaques with minimal scale due to the moist nature of these areas 2
Erythrodermic psoriasis, a severe form covering nearly the entire body surface area, can present with generalized erythema and varying degrees of scaling 2
Pustular psoriasis is characterized by collections of neutrophils large enough to be clinically apparent 2
Guttate psoriasis presents with small, salmon-pink papules with fine scale, primarily on the trunk and proximal extremities 2

Body mass index (BMI) may correlate with the presence and intensity of pruritus in psoriasis, with 40% of patients with pruritus being overweight and 10% obese 3
Environmental factors such as stress, systemic infections, and certain medications can trigger exacerbations of psoriasis and potentially worsen pruritus 4
The pathophysiology of pruritus in psoriasis involves neurogenic inflammation and neuropeptides, though other mediators may also play important roles 1

Treatment of psoriasis lesions often leads to relief of pruritus, as disease remission is typically linked with itch reduction 1
Topical therapies for pruritus in psoriasis include corticosteroids and vitamin D analogs, though their effect may be temporary 3
Phototherapy, particularly narrowband ultraviolet B (NB-UVB), has been shown to be effective in reducing pruritus in psoriasis 3
Biologic agents, including TNF inhibitors, have demonstrated efficacy in reducing itch intensity in psoriasis patients 1
Other treatment options include antihistamines (especially those with sedative effects) and antidepressants such as doxepin, mirtazapine, and paroxetine 1

The presence of significant pruritus in psoriasis should be recognized as an important symptom that requires appropriate assessment and management 2
Treatment decisions should consider not only the extent of skin involvement but also the impact of symptoms like pruritus on quality of life 5
A comprehensive approach to psoriasis management should address both the cutaneous manifestations and associated symptoms such as pruritus 6
Support from family members and healthcare professionals may help psoriasis patients cope with pruritus 1