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Central sensitization induces pain augmentation in chronic pain states. An analogous mechanism is speculated for chronic pruritus. This study compared patients with chronic pruritus (n = 79) of different origins (atopic dermatitis, chronic pruritus on non-lesional skin, chronic prurigo) and healthy controls (HC, n = 54) with regard to itch intensity and qualities of sensory symptoms after selective peripheral nerve fibre activation by electrical stimulation at 5 Hz (surrogate for C-fibre function) and 2,000 Hz (surrogate for Aβ-fibre function) using a Neurometer®. Electrically-induced itch was more intense in patients with chronic pruritus than in HC, but patients with chronic pruritus did not report "itch" more often than HC at 5 Hz. Stimulation at 2,000 Hz induced more pricking and tingling, but less throbbing in patients with chronic pruritus compared with HC. Treatment with cooling compound reduced clinical and experimental itch, but did not alter the distribution of sensory symptoms. These data show hyperknesis in chronic pruritus of various origins, arguing for common central sensitization mechanisms. [ABSTRACT FROM AUTHOR]

Crisaborole ointment is a nonsteroidal phosphodiesterase 4 inhibitor for the treatment of mild to moderate atopic dermatitis. Using pooled data from two phase 3 studies (NCT02118766/NCT02118792), mediation modeling determined the interrelationship among pruritus, quality of life (QoL), and treatment. Patients aged = 2 years received crisaborole ointment, 2%, or vehicle twice daily for 28 days. QoL measures were Dermatology Life Quality Index (DLQI) (= 16 years) and Children's Dermatology Life Quality Index (CDLQI) (2-15 years). Pruritus was assessed by the Severity of Pruritus Scale (4-point scale from 0 to 3). The indirect effect of crisaborole on QoL mediated through its effect on pruritus was 51% (DLQI model, p < 0.05) and 72% (CDLQI model, p < 0.05). Direct effect (other effects) on QoL was 49% (DLQI model, p < 0.05) and 28% (CDLQI model, p > 0.05). Mediation modeling shows that crisaborole affects QoL mostly indirectly through pruritus severity reduction. [ABSTRACT FROM AUTHOR]

Pruritus is a frequent symptom in medicine. Population-based studies show that every 5th person in the general population has suffered from chronic pruritus at least once in the lifetime with a 12-month incidence of 7%. In patient populations its frequency is much higher depending on the underlying cause, ranging from around 25% in haemodialysis patients to 100% in skin diseases such as urticaria and atopic dermatitis (AD). Pruritus may be the result of a dermatological or non-dermatological disease. Especially in non-diseased skin it may be caused by systemic, neurological or psychiatric diseases, as well as being a side effect of medications. In a number of cases chronic pruritus may be of multifactorial origin. Pruritus needs a precise diagnostic work-up. Management of chronic pruritus comprises treatment of the underlying disease and topical treatment modalities, including symptomatic antipruritic treatment, ultraviolet phototherapy and systemic treatment. Treating chronic pruritus needs to be targeted, multimodal and performed in a step-wise procedure requiring an interdisciplinary approach. We present the updated and consensus based (S2k) European guideline on chronic pruritus by a team of European pruritus experts from different disciplines. This version is an updated version of the guideline that was published in 2012 and updated in 2014 (www.euroderm. org). [ABSTRACT FROM AUTHOR]

Chronic pruritus can be a diagnostic sign of an underlying disease. In the intracutaneous histamine test, histamine (one of the best-known inducers of pruritus) may cause different reaction patterns depending on the underlying disease. The aim of this study was to determine if an intracutaneous injection of histamine can differentiate between the causes of chronic pruritus and thus be used as a diagnostic test in chronic pruritus of unknown aetiology. A total of 140 subjects with chronic pruritus with various dermatological, systemic or neurological diseases were included. The intracutaneous histamine test was performed once on each subject. Erythema, wheal and pruritus intensity were measured and analysed. Significantly greater wheal size was observed in patients with systemic or multifactorial causes. In general, there was a significant correlation between age and wheal size. Also, noticeable differences were found between males and females regarding pruritus and wheal size. In summary, the exact type of chronic pruritus could not be clearly determined based on the results of the intracutaneous histamine test. However, the results provide valuable insights into specific reaction patterns to experimental histamine-induced itch, e.g. sex-specific differences in the neurophysiology of pruritus, which should be considered in future studies. [ABSTRACT FROM AUTHOR]

This study was a prospective, parallel-group, randomized, double-blind, vehicle-controlled, multi-centre clinical trial to compare the efficacy of topical sertaconazole 2% cream with vehicle in reducing chronic pruritus in subjects with atopic dermatitis, and to assess its safety and local tolerability. A total of 70 subjects applied either of the 2 treatments twice daily for a period of 4 weeks on affected, itchy skin areas. Treatment efficacy was evaluated primarily considering the item itch intensity on a 5-point verbal rating scale. Insomnia, state of atopic dermatitis (Scoring Atopic Dermatitis; SCORAD), quality of life and therapy benefit were also assessed. No significant difference between active treatment and vehicle was found at any of the time-points for any of the investigated parameters. Under the experimental conditions of the study, sertaconazole 2% cream did not exert anti-pruritic effects that were better than vehicle in subjects with atopic dermatitis who had chronic pruritus. [ABSTRACT FROM AUTHOR]

Chronic pruritus is difficult to treat and requires the evaluation of new therapeutic modalities. We initiated an open-labelled, two-arm prospective, proof-of-concept study applying two selective serotonin re-uptake inhibitors on a long-term basis. Paroxetine and fluvoxamine were tested in a total of 72 pruritic patients (27 men, 45 women, age range 28-88 years, mean age 59.2 years). The reduction in pruritus was evaluated by analysis of visual analogue scores and determination of the maximal antipruritic effect (maximal percentual reduction in pruritus). Forty-nine of 72 patients (68.0%) experienced a weak (n=9), good (n= 16) or very good (n =24) antipruritic effect. Statistical analysis proved the efficacy of paroxetine and fluvoxamine with no significant difference. The best response was observed in patients with pruritus due to atopic dermatitis, systemic lymphoma and solid carcinoma. Chronic scratch lesions healed completely in 14/31 patients and partially in 17/31 patients. Adverse drug effects were observed in 70.8% of patients, resulting in discontinuation of treatment in 18 patients. These results support previous reports of high antipruritic potency of selective serotonin re-uptake inhibitors, which are a good alternative treatment modality in chronic pruritus. This should be confirmed in future double-blind studies. [ABSTRACT FROM AUTHOR]

Chronic pruritus is a symptom of many diseases, with studies pending investigating its prevalence or incidence. The aim of this study was to describe the characteristics of the underlying diseases in a large number of patients. A total of 263 patients (110 men, 153 women; age range 8-95 years; mean 55.9 years) were included in the study. The following data were collected from patients presenting over a 3-year period: gender, age, history, skin lesions, laboratory, histological and radiological investigations. An underlying dermatosis was identified in 41.8% of patients, a systemic disease including unidentified neoplasms in 13.3% and a neurological disorder in 0.4%. No disease was found in 44.5% of patients. Among the patients in whom no disease was found, 55.6% of the, mainly elderly, patients had an accumulation of many co-factors, suggesting an own subgroup with multifactorial origin for the pruritus. The distribution and type of secondary scratch lesions gave no clue as to the underlying disease. In conclusion, patients with chronic pruritus present a inhomgeneous collective with different underlying diseases, including malignancy, necessitating thorough investigation. [ABSTRACT FROM AUTHOR]