Chronic generalized pruritus without primary skin lesions: a longitudinal prospective observational study

The impact of underlying diseases-related drugs on the chronic kidney disease-associated pruritus in hemodialysis patients

Background

Uremic pruritus or chronic kidney disease-associated pruritus (CKD-aP) is a frequent compromising symptom in end-stage renal disease. Despite the little attention paid to drugs used among hemodialysis (HD) patients, investigating medications used in this population of patients and examining the status of CKD-aP may lead to the identification of medications that improve or worsen the pruritus condition. We aimed to assess the role of underlying diseases-related drugs on CKD-aP in HD patients.

Materials and Methods

We performed a case - control study on HD patients aged over 18 years old. The demographic data and clinical parameters including HD parameters, drug history, dermatologic assessments, and laboratory examination were assessed.

Results

We compared 128 patients with CKD-aP as cases and 109 patients without CKD-aP as controls. Cases were on the longer course of dialysis (44.69 ± 43.24 months for cases vs. 38.87 ± 50.73 months for controls; P = 0.02). In multiple analyses of variables related to CKD-aP, backward LR logistic regression revealed that only atorvastatin (P = 0.036) was considered to be a predictive factor associated with CKD-aP. Thus, the use of atorvastatin reduced the index of CKD-aP (95% confidence interval: 0.256-0.954, odd's Ratio = 0.494).

Conclusion

Atorvastatin was associated with decreased frequencies of CKD-aP among HD patients in our study. This knowledge may guide further clinical trials to evaluate atorvastatin's immunomodulatory and anti-inflammatory effects on the CKD-aP in HD populations.

Study of the Involvement of the P2Y12 Receptor in Chronic Itching in Type 2 Diabetes Mellitus

Itching is a common clinical symptom in diabetic patients. This research is to carry out experiments on the pathological changes in the P2Y12 receptor in type 2 diabetes mellitus complicated with chronic itching. Changes in body weight, fasting blood glucose (FBG), thermal hyperalgesia, cold hyperalgesia, spontaneous itching, and sciatic nerve conduction velocity were detected. The content of reactive oxygen species (ROS) in the dorsal root ganglion was detected by chemical fluorescence. The expression of the P2Y12 receptor, NLRP3, ASC, interleukin-1β (IL-1β), and IL-18 was detected by Western blotting, real-time quantitative PCR, immunofluorescence double labelling, and enzyme-linked immunosorbent assay. Itching and pain behaviours of the mice in the type 2 diabetes mellitus + itch group were significantly increased, and the expression of P2Y12 and NLRP3 as well as the content of ROS increased, and these changes were significantly reversed by treatment with P2Y12 short hairpin RNA (shRNA) or P2Y12 antagonist ticagrelor. Upregulated P2Y12 receptor expression after the activation of satellite glial cells contributes to the increase in ROS content in vivo, followed by NLRP3 inflammasome activation, increased inflammatory cytokine release, and damage to peripheral nerves, which leads to chronic itching. Treatment with P2Y12 shRNA or ticagrelor can inhibit these pathological changes, thus improving itching behaviour. Development mechanism of diabetes mellitus complicated with chronic itching. Notes: The upregulation of P2Y12 receptor expression and the activation of SGCs lead to the increase of ROS content in vivo, followed by the activation of NLRP3 inflammasome, the increase of inflammatory cytokine release, the abnormal excitation of DRG neurons, and the damage of peripheral nerves, resulting in chronic itching. P2Y12 receptor-related inflammatory injury involves chronic itching in type 2 diabetes mellitus. Treatment with P2Y12 receptor shRNA or P2Y12 antagonist ticagrelor can inhibit these pathological changes and improve itching behaviour.

Itch in Adult Population with Type 2 Diabetes Mellitus: Clinical Profile, Pathogenesis and Disease-Related Burden in a Cross-Sectional Study

BACKGROUND

Despite growing interest in itch, data regarding itch in type 2 diabetes mellitus (DM2) are still limited, and mostly based on outdated studies. This study aimed to evaluate the clinical characteristics of itch in the adult population with DM2 and explore potential underlying causes.

METHODS

The study group consisted of 109 adult patients with DM2. Standardized questionnaires were completed in order to assess the itch intensity [Numerical Rating Scale (three days, 24hours) (NRS)] and the Four-item Itch Questionnaire (4IIQ) and to assess the psychological impact of itch [ItchyQoL, Six-Item Stigmatization Scale (6-ISS), Hospital Anxiety and Depression Scale (HADS)]. Skin dryness was evaluated clinically and by non-invasive assessment of epidermis moisturizing. Neuropathy was assessed using the clinical Katzenwadel neuropathy scale.

RESULTS

Itch occurred in 35.8% of adult patients with DM2, with NRSmax three days 6.31 ± 2.16 and 8.1 ± 3.5 points in 4IIQ. Itchy patients have had significantly higher FPG levels compared with the non-itchy population (p = 0.01). Patients with itch had a significantly higher possibility of neuropathy compared with non-itchy subjects (p < 0.01). Skin xerosis was significantly more advanced in patients with itch compared to those without (p < 0.01). The mean ItchyQol score was assessed as 41.2 ± 13.4 points, indicating mild life quality impairment and correlated positively with itch intensity. Itchy subjects had significantly higher scores in both anxiety and depression dimensions of HADS (in each p < 0.01).

CONCLUSIONS

We suggest that the primary cause of itch is prolonged poor diabetes control with altered glucose and insulin levels, subsequently causing skin dryness and neuropathy in long-lasting DM2.

Pruritus is common in patients with chronic liver disease and is improved by nalfurafine hydrochloride

Pruritus is known to be a common complication in hepatitis patients, but the exact frequency and degree are not fully elucidated. Thus, we evaluated pruritus of 450 patients with chronic liver disease at our hospital. Pruritus was observed in 240 (53%) of the patients. Pruritus was significantly associated with males (OR = 1.51, P = 0.038) and patients with alkaline phosphatase (ALP) ≥ 200 U/L (OR = 1.56, P = 0.0495) and was significantly less in HBsAg-positive patients (OR = 0.449, P = 0.004). Seasonally, there was no difference in the frequency of pruritus between summer and winter. Of the 24 refractory pruritus patients treated with nalfurafine, 17 (71%) indicated improvement of itch, which is defined as a decrease in the visual analog scale score ≥ 30 mm. Pruritus was improved by nalfurafine both during daytime and nighttime in the Kawashima’s scores evaluation. All patients who received nalfurafine exhibited improved Kawashima’s scores ≥ 1 point during the daytime or nighttime. In conclusion, pruritus occurred in > 50% of patients with chronic liver disease, and predictors of pruritus were males and ALP ≥ 200 U/L. Nalfurafine may be useful for pruritus, regardless of whether daytime or nighttime.

[Neuropathic pruritus]

In the past 10 years specific pathways for pruritus have been characterized on a cellular and molecular level but their exact role in the pathophysiology of neuropathic pruritus remains unclear. This also applies to the question which of the competing theories for pruritus, e.g. specificity, temporal/spatial pattern or intensity, would best apply. While experimental trials on mice have mostly confirmed the theory of specificity, the results on humans indicate a role of spatial and temporal patterns. The skin innervation is greatly reduced by the neuropathy and could provide a "spatial contrast pattern" and the axotomy could induce a de novo expression of gastrin-releasing peptide (GRP) in primarily afferent nociceptors and thus modulate spinal pruritus processing. In addition, the overlap of pruritus and pain in neuropathy patients complicates the direct translation from animal experiments and requires collaboration at the clinical level between pain medicine and dermatology.

Itch in Children with Type 1 Diabetes: A Cross-Sectional Study

INTRODUCTION

Type 1 diabetes (T1D) is reported to be one of the most common medical conditions in school-age youth and is ranked third in the prevalence of pediatric conditions. Only a few studies have investigated the occurrence of itch in diabetes mellitus, reporting conflicting data. The purpose of this study was to investigate the prevalence of itch in T1D to provide itch characteristics and to explore the potential underlying causes.

METHODS

This prospective study evaluated itch among 100 children with T1D. Itch intensity was assessed with the Numerical Rating Scale (NRS) and the 4-Item Itch Questionnaire (4IIQ). The Children's Dermatology Life Quality Index (CDLQI) was implemented to assess the quality of life issues. Various clinical features and factors influencing itch were also examined. Skin dryness was evaluated clinically by non-invasive assessment of epidermis moisturizing.

RESULTS

Itch occurred in 22% of children with T1D with the mean maximal intensity of 5.9 ± 3.0 points in NRS and 6.7 ± 3.5 points in 4IIQ (median, 5.5 points). In the majority of patients, the itch was limited to a few regions of the body; usually, the upper limbs (68.2%) were affected, followed by the lower limbs (50%) and the trunk (31.8%). Clinically examined skin xerosis was significantly more advanced in children with itch compared with those without itch (p < 0.01). The mean CDLQI score in the itchy group was 4.0 ± 4.7 points (median, 2.5 points), indicating a small impairment of quality of life. The intensity of itch (both NRS last 3 days and NRS last 24 h) correlated positively with life quality impairment (R = 0.7; p = 0.015 and R = 0.8, p = 0.002, respectively).

CONCLUSIONS

Our study found itch as a moderately frequent symptom in children with T1D; however, itch presence and intensity may relevantly debilitate quality of life among subjects. We suggest that dryness of the skin may play a role in the pathogenesis of itch in this population.

Manifestaciones dermatológicas de la diabetes: clasificación y diagnóstico

Se estima que en Colombia hay 2.836.500 adultos con diabetes, una enfermedad con una prevalencia del 8,4 %. La exposición a niveles elevados de glucosa afecta los procesos de proliferación y diferenciación en las células de todos los órganos y tejidos, así mismo en los queratinocitos, fibroblastos y demás células presentes en la piel, alteraciones que ocurren en más de un tercio de los diabéticos y que pueden ser la manifestación inicial de la enfermedad. La frecuencia y presentación de estas dermatosis varía según la población estudiada. La dermopatía diabética, la acantosis nigricans, los fibromas laxos, el prurito y la xerosis son las formas más comunes y se consideran marcadores cutáneos de la diabetes. La presente revisión se enfoca en las manifestaciones dermatológicas específicas y no específicas de la diabetes, así como en las relacionadas con su tratamiento. Estas pueden ser un reflejo del estado metabólico actual o previo del paciente diabético y su oportuna identificación permite orientar el diagnóstico primario, sospechar un estado rediabético u optimizar el tratamiento de la enfermedad en los individuos ya diagnosticados.