Pathomechanism of Pruritus in Psoriasis and Atopic Dermatitis: Novel Approaches, Similarities and Differences.

Pruritus is defined as an unpleasant sensation that elicits a desire to scratch. Nearly a third of the world's population may suffer from pruritus during their lifetime. This symptom is widely observed in numerous inflammatory skin diseases-e.g., approximately 70-90% of patients with psoriasis and almost every patient with atopic dermatitis suffer from pruritus. Although the pathogenesis of atopic dermatitis and psoriasis is different, the complex intricacies between several biochemical mediators, enzymes, and pathways seem to play a crucial role in both conditions. Despite the high prevalence of pruritus in the general population, the pathogenesis of this symptom in various conditions remains elusive. This review aims to summarize current knowledge about the pathogenesis of pruritus in psoriasis and atopic dermatitis. Each molecule involved in the pruritic pathway would merit a separate chapter or even an entire book, however, in the current review we have concentrated on some reports which we found crucial in the understanding of pruritus. However, the pathomechanism of pruritus is an extremely complex and intricate process. Moreover, many of these signaling pathways are currently undergoing detailed analysis or are still unexplained. As a result, it is currently difficult to take an objective view of how far we have come in elucidating the pathogenesis of pruritus in the described diseases. Nevertheless, considerable progress has been made in recent years.

Characteristics of pruritus in various clinical variants of psoriasis: Final report of the binational, multicentre, cross-sectional study.

BACKGROUND: Pruritus, which is the most frequent subjective symptom of psoriasis, may cause significant discomfort, embarrassment and even interfere with patients normal daily activities. However, the perception of itch in various psoriasis subtypes remains unknown. OBJECTIVES: The aim of this study was to investigate and to characterize pruritus in different clinical variants of psoriasis. METHODS: This cross-sectional, binational, multicentre study included 295 subjects suffering from nine different clinical subtypes of psoriasis: large-plaque psoriasis (n = 45), nummular psoriasis (n = 32), guttate psoriasis (n = 31), scalp psoriasis (n = 32), inverse psoriasis (n = 23), erythrodermic psoriasis (n = 33), palmoplantar psoriasis vulgaris (n = 33), palmoplantar pustular psoriasis (n = 42) and generalized pustular psoriasis (n = 23). Measures included sociodemographic and anthropometric data, detailed pruritus characteristics including but not limited to pruritus intensity, frequency and extend, as well as psoriasis severity. RESULTS: The lifetime prevalence of pruritus in each clinical variant of psoriasis was similar and quite high, reaching up to 100% in some disease subtypes (i.e., nummular psoriasis, scalp psoriasis and generalized pustular psoriasis). Psoriasis severity correlated with pruritus intensity in scalp psoriasis, palmoplantar pustular psoriasis and generalized pustular psoriasis. The age, duration of psoriasis and BMI did not interfere with the intensity of itch. CONCLUSIONS: Pruritus is highly prevalent in each clinical variant of psoriasis. However, the sensation of itch is very individual, difficult to universally describe even in the same subtype.

The Impact of Pruritus on the Quality of Life and Sleep Disturbances in Patients Suffering from Different Clinical Variants of Psoriasis.

BACKGROUND: Quality of life (QoL) and sleep, which are essential for well-being in the mental, physical, and socioeconomic domains, are impaired in psoriatic patients. However, the exact role of the clinical subtype of psoriasis in this aspect remains poorly studied. OBJECTIVES: The aim of this study was to investigate differences in QoL impairment and sleeping problems in patients suffering from various clinical subtypes of psoriasis and to evaluate the effects of pruritus on QoL. METHODS: This cross-sectional, multicenter study included 295 eligible subjects with diagnosed psoriasis. Each patient was examined with the use of the same questionnaire. Measures included predominant subtype of psoriasis, disease severity, pruritus scores, patients' health-related QoL and the incidence of sleep disturbance. RESULTS: The QoL of most patients was decreased irrespectively of clinical psoriasis subtype, however, the most impaired QoL was in patients with erythrodermic psoriasis. The majority of patients reported sleep disturbances caused by pruritus, albeit there was no relevant differences between analyzed subgroups in this aspect of patients' well-being. Pruritus was an important factor determining QoL and sleeping problems in the studied population. CONCLUSIONS: Identifying the most disturbing area of life and recognizing the most bothersome subjective symptoms of psoriasis are pivotal to focusing on the most relevant treatment goal and achieving therapeutic success.

COVID-19 and Postural Control-A Stabilographic Study Using Rambling-Trembling Decomposition Method.

Background and Objectives: Some respiratory viruses demonstrate neurotropic capacities. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has recently taken over the globe, causing coronavirus disease 2019 (COVID-19). The aim of the study was to evaluate the impact of COVID-19 on postural control in subjects who have recently recovered from the infection. Materials and Methods: Thirty-three convalescents who underwent COVID-19 within the preceding 2-4 weeks, and 35 healthy controls were enrolled. The ground reaction forces were registered with the use of a force platform during quiet standing. The analysis of the resultant center of foot pressure (COP) decomposed into rambling (RAMB) and trembling (TREMB) and sample entropy was conducted. Results: Range of TREMB was significantly increased in subjects who experienced anosmia/hyposmia during COVID-19 when the measurement was performed with closed eyes (p = 0.03). In addition, subjects who reported dyspnea during COVID-19 demonstrated significant increase of length and velocity of COP (p < 0.001), RAMB (p < 0.001), and TREMB (p < 0.001), indicating substantial changes in postural control. Conclusions: Subjects who had experienced olfactory dysfunction or respiratory distress during COVID-19 demonstrate symptoms of balance deficits after COVID-19 recovery, and the analysis using rambling-trembling decomposition method might point at less efficient peripheral control. Monitoring for neurological sequelae of COVID-19 should be considered.

Characteristics of Pruritus in Various Clinical Variants of Psoriasis: Results of the Multinational, Multicenter, Cross-Sectional Study.

Psoriasis is a chronic, inflammatory skin disease present in about 3% of the world's population. The clinical symptoms manifest diversely, therefore one can distinguish several subtypes of psoriasis. The majority of patients with psoriasis experience pruritus, which is an unpleasant sensation that decreases patients' quality of life. The knowledge on pruritus in different subtypes of psoriasis is limited. We have performed a cross-sectional, prospective, and multicenter study to evaluate the relationship between clinical subtypes of psoriasis (large-plaque, nummular, guttate, palmoplantar, inverse, erythrodermic, palmoplantar pustular, generalized pustular psoriasis, and psoriasis of the scalp) and the prevalence, intensity, and clinical manifestation of itch. We introduced a questionnaire assessing various aspects of pruritus to a total of 254 patients. Out of these, 42 were excluded. Pruritus was present in 92.9% of the remaining patients and its prevalence did not depend on the clinical subtype. A correlation between the severity of psoriasis and the intensity of itch was explicitly noticeable in palmoplantar pustular psoriasis and scalp psoriasis (p < 0.05). The itch sensation was individual and differed among subtypes of psoriasis. In conclusion, pruritus is a frequent phenomenon, and its presentation is different in various subtypes of psoriasis.

Molecular Aspects of Pruritus Pathogenesis in Psoriasis.

Psoriasis is a chronic, systemic inflammatory disease with a genetic background that involves almost 3% of the general population worldwide. Approximately, 70-90% of patients with psoriasis suffer from pruritus, an unpleasant sensation that provokes a desire to scratch. Despite the enormous progress in understanding the mechanisms that cause psoriasis, the pathogenesis of psoriasis-related pruritus still remains unclear. In order to improve patients' quality of life, development of more effective and safer antipruritic therapies is necessary. In turn to make it possible, better understanding of complexed and multifactorial pathogenesis of this symptom is needed. In this article we have systematized the current knowledge about pruritus origin in psoriasis.

Quality of Life in Patients with Morphea: A Cross-Sectional Study and a Review of the Current Literature.

OBJECTIVE: The aim of the study was to evaluate QoL in patients suffering from morphea. Material and Methods. Sixty-five patients with morphea were recruited into this cross-sectional, prospective parallel study. QoL among adult patients was assessed with the Dermatology Life Quality Index (DLQI) and Euro-QoL-5D questionnaire; patients aged <17 years used the Children's Dermatology Life Quality Index (CDLQI). The severity of morphea was assessed using the Localized Scleroderma Cutaneous Assessment Tool. The results of QoL and its association with disease severity were compared between patients with various morphea subtypes. RESULTS: The mean DLQI scoring was 3.8 ± 4.1 points and the CDLQI was 2.3 ± 3.0. The mean value of Visual Analogue Scale thermometer (EQ VAS) was 66.9 ± 17.5 points. The disease activity of morphea based on mLoSSI correlated significantly with QoL impairment according to the DLQI (R = 0.41, p = 0.001). No significant correlation was observed between morphea-induced damage and QoL (p = 0.99). CONCLUSIONS: Evaluation of QoL in patients with morphea is still challenging due to lack of good assessment tools dedicated specifically for morphea patients. In general, QoL in morphea patients is significantly correlated with the disease activity, but not with disease-induced skin damage.

NK-1 Receptor Antagonists and Pruritus: Review of Current Literature.

The discovery of the first neurokinin 1 (NK-1) receptor antagonist was a turning point in the prevention of chemotherapy-induced nausea and vomiting. The NK-1 antagonists are a novel class of drugs that possess antidepressant, anxiolytic, and antiemetic properties. Recently, clinicians have also described an anti-itch activity of NK-1 antagonists. We present herein results from currently available data on use of NK-1R antagonists in dermatology. For this purpose, a systemic electronic literature search of the PubMed and CINAHL databases, Cochrane Library, and clinicaltrials.gov website was performed. Based on currently available data, it can be concluded that NK-1 inhibitors show significant antipruritic potential for treatment of chronic pruritus in different dermatological conditions, but further studies are needed to establish the best indications and dosage of these drugs.

Rheumatoid neutrophilic dermatitis.

Rheumatoid neutrophilic dermatitis is a rare extra-articular manifestation of rheumatoid arthritis, both seropositive and seronegative for rheumatoid factor. The condition most often presents as symmetric erythematous papules, nodules, plaques, and urticaria-like lesions in patients with severe, long-lasting rheumatoid arthritis. We report a case of a 65-year-old man with well-controlled rheumatoid arthritis, who developed rheumatoid neutrophilic dermatitis on the right lower leg. The biopsy of skin lesions revealed an intense, neutrophilic dermal infiltrate, microabscesses, and leukocytoclasis without vasculitis. The patient responded well to pulses of intravenous methylprednisolone. We present this patient due to the rarity of the disease and atypical unilateral manifestation involving the flexural surfaces of the lower leg.