Clinical Characteristics of Pruritus in Patients with Scalp Psoriasis and Their Relation with Intraepidermal Nerve Fiber Density

Abstract

BackgroundThe scalp is frequently affected in psoriasis patients, and pruritus can adversely affect the quality of life of affected patients. Few studies have assessed pruritus in scalp psoriasis.ObjectiveTo determine the correlation among the clinical characteristics of pruritus, psoriasis scalp severity index (PSSI), and intraepidermal nerve fiber (IENF) density in psoriatic scalp lesions.MethodsEighty patients (53 men, 27 women; mean age, 46.4 years; mean PSSI, 19.9) with scalp psoriasis were evaluated by using the PSSI and the Leuven itch scale. Biopsies were obtained from the lesional and nonlesional skin of 19 patients (10 men, 9 women; mean age, 37.8 years; mean PSSI, 25.8). Immunofluorescence staining of protein gene product 9.5 was performed to determine the IENF density.ResultsSixty-four patients (80%) complained of pruritus associated with scalp psoriasis, which negatively affected their quality of life to varying degrees. A moderate positive relation between PSSI score and pruritus intensity was identified (r=0.225 and p=0.044). The IENF density in psoriatic lesions was significantly higher than that in the nonlesional scalp (6.2±1.2 vs. 4.2±1.6, p<0.001). However, the correlations between IENF density and PSSI score, and IENF density and pruritus intensity were insignificant.ConclusionThese results indicate that pruritus prevalence is high in patients with scalp psoriasis, and pruritus considerably influences the patients' daily lives and quality of life. In addition, high IENF density in psoriatic scalp lesions may play a role in the development of pruritus in scalp psoriasis.

Pruritus in psoriasis: An update

“…Recently, it was also found that blocking Trk-A might be a valuable strategy for future antipruritic therapies. Recently, it was also suggested that increased epidermal nerve density in psoriatic scalp lesions may play a role in the development of pruritus in scalp psoriasis (Kim et al, 2014). In addition, increased innervation density in psoriasis induced by NGF may decrease the threshold for pruritic stimuli.…”

“…In some patients generalized pruritus is observed involving the entire body surface (Yosipovitch et al, 2000;Szepietowski et al, 2002;Amatya et al, 2008;Kim et al, 2014). Several authors documented a significant correlation between pruritus intensity and psoriasis severity (Szepietowski et al, 2002;Sampogna et al, 2004;Chang et al, 2007;Kou et al, 2012;Kim et al, 2014); however, not all researchers were able to confirm such a correlation (Yosipovitch et al, 2000). The mean severity of pruritus assessed according to the visual analogue scale (VAS) ranged from 4.2 to 6.4 points (Yosipovitch et al, 2000;Reich et al, 2003;Amatya et al, 2008); thus, it can be assumed that most patients with psoriasis suffer from pruritus of moderate severity.…”

“…Recently, it was also suggested that increased epidermal nerve density in psoriatic scalp lesions may play a role in the development of pruritus in scalp psoriasis (Kim et al, 2014).…”

Scalp Itch: A Systematic Review

“…Specifically, scalp itch has been reported in up to 80% of patients with psoriasis, and there is positive correlation between the severity of the lesions in scalp psoriasis and the severity of itch [19] . Possible mechanisms that explain pruritus in scalp psoriasis are hyperinnervation, neurogenic inflammation, neuropeptide misbalance, abnormal functioning of the peripheral opioid system, cytokine release, and vascular abnormalities [20,21] . Regarding quality of life, pruritus is considered by patients as the most important factor that impairs the ability to work, with a negative impact on concentration in 52.5% of patients [15,22] .…”

“…Regarding quality of life, pruritus is considered by patients as the most important factor that impairs the ability to work, with a negative impact on concentration in 52.5% of patients [15,22] . The characteristics of pruritus in scalp psoriasis are variable: most of the patients refer intermittent pruritus, and the most important exacerbating factors are stress and temperature [21] .…”