Truncal pruritus of unknown origin may be a symptom of diabetic polyneuropathy

Topical delivery of insulin using novel organogel formulations: An approach for the management of diabetic wounds

Diabetes mellitus is a growing chronic form of diabetes, with lengthy health implications. It is predicted as poor diabetic wound recovery affects roughly 25% of all diabetes mellitus patients, frequently resulting in lower traumatic injury and severe external factors and emotional expenses. The insulin-resistant condition increases biofilm development, making diabetic wounds harder to treat. Nowadays, medical treatment and management of diabetic wounds, which have a significant amputation rate, a high-frequency rate, and a high death rate, have become a global concern. Topical formulations have played a significant part in diabetic wound management and have been developed to achieve a number of features. Because of its significant biocompatibility, moisture retention, and therapeutic qualities, topical insulin has emerged as an appealing and feasible wound healing process effector. With a greater comprehension of the etiology of diabetic wounds, numerous functionalized topical insulins have been described and shown good outcomes in recent years, which has improved some diabetic injuries. The healing of wounds is a physiological phenomenon that restores skin integrity and heals damaged tissues. Insulin, a powerful wound-healing factor, is also used in several experimental and clinical studies accelerate healing of diverse injuries.

Guideline for the Management of Diabetes Mellitus in the Elderly in China (2024 Edition)

With the deepening of aging in China, the prevalence of diabetes in older people has increased noticeably, and standardized diabetes management is critical for improving clinical outcomes of diabetes in older people. In 2021, the National Center of Gerontology, Chinese Society of Geriatrics, and Diabetes Professional Committee of Chinese Aging Well Association organized experts to write the first guideline for diabetes diagnosis and treatment in older people in China, the Guideline for the Management of Diabetes Mellitus in the Elderly in China (2021 Edition). The guideline emphasizes that older patients with diabetes are a highly heterogeneous group requiring comprehensive assessment and stratified and individualized management strategies. The guideline proposes simple treatments and de-intensified treatment strategies for older patients with diabetes. This edition of the guideline provides clinicians with practical and operable clinical guidance, thus greatly contributing to the comprehensive and full-cycle standardized management of older patients with diabetes in China and promoting the extensive development of clinical and basic research on diabetes in older people and related fields. In the past 3 years, evidence-based medicine for older patients with diabetes and related fields has further advanced, and new treatment concepts, drugs, and technologies have been developed. The guideline editorial committee promptly updated the first edition of the guideline and compiled the Guideline for the Management of Diabetes Mellitus in the Elderly in China (2024 Edition). More precise management paths for older patients with diabetes are proposed, for achieving continued standardization of the management of older Chinese patients with diabetes and improving their clinical outcomes.

[Management of pruritus in the elderly]

BACKGROUND

Chronic pruritus (CP), a frequent (20.3%) symptom in the elderly, increases with age. It has a significant impact on the quality of life, ranking among the 50 most burdensome diseases worldwide (Global Burden of Disease Study).

OBJECTIVES

The aim is to provide an overview of the symptom CP in the elderly and to improve differentiation of underlying conditions and management of this entity.

MATERIALS AND METHODS

A literature search in PubMed was performed, using the terms 'pruritus', 'elderly' and 'gerontodermatology'.

RESULTS

The main causes of CP in the elderly are the physiologic aging process (xerosis cutis, immunosenescence, neuropathy), the increase in potentially pruritic diseases with increasing age (diabetes mellitus, chronic renal failure), and polypharmacy. Therapeutic options relate to causes, severity of pruritus, and individual patient factors (multimorbidity, impaired organ function). The recently updated S2k guideline 'Diagnosis and therapy of chronic pruritus' is helpful.

CONCLUSION

CP in the elderly is challenging for both patients and physicians. Not only the difficulty of identifying the underlying cause, but the complexity of treatment and its tolerability and practicability determines these patients' further burden.

Multifactorial causes of chronic itch in diabetes: More than just neuropathy

BACKGROUND

Chronic pruritus is common in patients with diabetes though its pathophysiology is unknown and difficult to pinpoint given the multi-system manifestations of diabetes. Herein, we aim to evaluate the severity of chronic itch in patients with diabetes and its association with glycaemic control, microvascular complications and quality of life.

METHODS

We conducted a retrospective study of 105 adults with diabetes evaluated by a dermatologist at a tertiary care centre in Mexico City. Degree of chronic pruritus and its impact on quality of life as well as laboratory, clinical and demographic data were collected. Patients without chronic pruritus (n = 62) were compared to those with chronic pruritus (n = 43). The latter cohort was further stratified by itch severity, and characteristics of their itch were quantified.

RESULTS

Neuropathy and loss of protective sensation were more common in patients with chronic pruritus, compared to those without chronic pruritus (p = 0.007 and p = 0.001, respectively). Anxiety and depression were more common in individuals with chronic pruritus (p = 0.009), and these group reported higher effect of pruritus on their quality of life (p < 0.0001). The most common sites of itch were the head, back and arms. Among patients with chronic itch, increasing itch severity was associated with decreasing eGFR (p = 0.080).

CONCLUSIONS

The underlying cause of chronic itch in patients with diabetes is likely multifactorial and owing to microvascular complications such as neuropathy and nephropathy. Better understanding of the causes of itch in these patients can allow for more targeted treatment, leading to improved quality of life.

Evolving spectrum of diabetic wound: Mechanistic insights and therapeutic targets

Diabetes mellitus is a chronic metabolic disorder resulting in an increased blood glucose level and prolonged hyperglycemia, causes long term health conse-quences. Chronic wound is frequently occurring in diabetes patients due to compromised wound healing capability. Management of wounds in diabetic patients remains a clinical challenge despite many advancements in the field of science and technology. Increasing evidence indicates that alteration of the biochemical milieu resulting from alteration in inflammatory cytokines and matrix metalloproteinase, decrease in fibroblast and keratinocyte functioning, neuropathy, altered leukocyte functioning, infection, etc., plays a significant role in impaired wound healing in diabetic people. Apart from the current pharmacotherapy, different other approaches like the use of conventional drugs, antidiabetic medication, antibiotics, debridement, offloading, platelet-rich plasma, growth factor, oxygen therapy, negative pressure wound therapy, low-level laser, extracorporeal shock wave bioengineered substitute can be considered in the management of diabetic wounds. Drugs/therapeutic strategy that induce angiogenesis and collagen synthesis, inhibition of MMPs, reduction of oxidative stress, controlling hyperglycemia, increase growth factors, regulate inflammatory cytokines, cause NO induction, induce fibroblast and keratinocyte proliferation, control microbial infections are considered important in controlling diabetic wound. Further, medicinal plants and/or phytoconstituents also offer a viable alternative in the treatment of diabetic wound. The focus of the present review is to highlight the molecular and cellular mechanisms, and discuss the drug targets and treatment strategies involved in the diabetic wound.

[Systemic pruritus: what is new in diagnosis and treatment?]

BACKGROUND

Chronic pruritus is a common symptom of various systemic diseases. In particular, patients with chronic renal failure, hepatobiliary diseases, and myeloproliferative neoplasms are affected.

OBJECTIVES

The purpose of this review is to provide an overview of laboratory chemistry and imaging diagnostics as well as current and novel therapeutic approaches to pruritus of systemic diseases.

MATERIALS AND METHODS

An extensive PubMed search was performed.

RESULTS

To clarify the cause of chronic pruritus, a step-by-step diagnosis is recommended, which is based on the frequency of pruritus-associated diseases. A basic diagnosis enables a cost-effective and targeted clarification at the level of a general practitioner. Current topical and drug therapy recommendations of pruritus in chronic renal failure, hepatobiliary diseases, myeloproliferative neoplasms, and rarer causes are summarized. In addition, novel therapeutic approaches such as the κ‑opioid receptor agonist difelikefalin, bezafibrate, inhibitors of the ileal bile acid transporter (IBAT), and the JAK-STAT pathway are highlighted.

CONCLUSIONS

Chronic pruritus in systemic diseases can be a diagnostic challenge. A staged diagnostic approach facilitates identification of the underlying disease. Improved pathophysiological understanding has led to the first approved therapeutic options for chronic kidney disease-associated and hepatic pruritus.

Neuroinflammation Involved in Diabetes-Related Pain and Itch

Diabetes mellitus (DM) is a global epidemic with increasing incidence, which results in diverse complications, seriously affects the patient quality of life, and brings huge economic burdens to society. Diabetic neuropathy is the most common chronic complication of DM, resulting in neuropathic pain and chronic itch. The precise mechanisms of diabetic neuropathy have not been fully clarified, hindering the exploration of novel therapies for diabetic neuropathy and its terrible symptoms such as diabetic pain and itch. Accumulating evidence suggests that neuroinflammation plays a critical role in the pathophysiologic process of neuropathic pain and chronic itch. Indeed, researchers have currently made significant progress in knowing the role of glial cells and the pro-inflammatory mediators produced from glial cells in the modulation of chronic pain and itch signal processing. Here, we provide an overview of the current understanding of neuroinflammation in contributing to the sensitization of the peripheral nervous system (PNS) and central nervous system (CNS). In addition, we also summarize the inflammation mechanisms that contribute to the pathogenesis of diabetic itch, including activation of glial cells, oxidative stress, and pro-inflammatory factors. Targeting excessive neuroinflammation may provide potential and effective therapies for the treatment of chronic neuropathic pain and itch in DM.

Scalp dysesthesia: a neuropathic phenomenon

Scalp dysesthesia is an abnormal sensation of the scalp in the absence of cutaneous disease. It is characterized by a burning and/or itching sensation and can be related to a variety of neurogenic or psychogenic causes. This condition is extremely bothersome and is also common- especially amongst the geriatric population, in women, in patients with diabetes mellitus and patients with psychiatric history. However, despite its prevalence in many populations, there is limited data about its causes and characteristics. Given its limited cutaneous manifestations it is also easily misdiagnosed and an underrecognized cause of scalp pruritus in the dermatological community. Therefore, education on scalp dysesthesia is paramount to helping physicians identify and provide appropriate treatment for these patients. This review focuses predominately on the neurogenic causes (with a brief review of psychogenic itch) of scalp dysesthesia and the therapeutics that have been found to be effective for this condition. Neurogenic causes of scalp dysesthesia occur with damage to the central or peripheral pathways of itch sensation, resulting in modification and heightened sensitivity of nerves that result in abnormal sensations in the absence of or out of proportion to external stimuli. A comprehensive review of etiologies is provided here, ranging from lesions to the central nervous system caused by cervical spine disease, trigeminal trophic syndrome, tumor, stroke, and multiple sclerosis, to small fiber neuropathies caused by diabetes, brow lifts, keloid and burn scarring. Recently, there have also been reports of scalp dysesthesias associated with post-infectious COVID-19. Treatment options tailored towards disease severity and different causes of disease will also be discussed. By elucidating the different mechanisms and therapeutic treatments of scalp dysesthesia, we hope to provide clinicians with the tools to identify and treat this condition as well as encourage further research into its etiologies and therapeutics.

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.

Knowledge, Attitude and Practice for Pruritus Management in Physicians and Patients with Diabetes

Pruritus is a common dermatological condition observed in patients with diabetes, making it a dermatometabolic condition. Being multiaethiological, pruritis is caused by autoimmune, genetic, infectious and various systemic diseases. The present survey aimed to understand the knowledge, attitude and practice toward pruritus among Indian physicians and patients with diabetes presenting with pruritus. A telephonic, cross-sectional, qualitative survey was conducted among physicians and patients across five cities in India from July-August 2020. An open-ended discussion guide was used for the interview; the data were analyzed to check for common themes and trends. A majority of the consulting physicians (CPs) believed that uncontrolled diabetes is the main causal factor for pruritus in patients with diabetes and reported that currently there are no standard tests or treatment guidelines for its management. CPs emphasized proper monitoring and counseling to overcome current challenges. Patients reported a negative impact of pruritus on their daily activities and quality of life. The survey concluded that poor management of diabetes is one of the main causal factors for patients with diabetes presenting with pruritus in India. CPs emphasized controlling diabetes along with symptomatic treatment. For patients, pruritus has multifaceted effects on their health, overall well-being, and quality of life.

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.

Diabetic Wound-Healing Science

Diabetes mellitus is an increasingly prevalent chronic metabolic disease characterized by prolonged hyperglycemia that leads to long-term health consequences. It is estimated that impaired healing of diabetic wounds affects approximately 25% of all patients with diabetes mellitus, often resulting in lower limb amputation, with subsequent high economic and psychosocial costs. The hyperglycemic environment promotes the formation of biofilms and makes diabetic wounds difficult to treat. In this review, we present updates regarding recent advances in our understanding of the pathophysiology of diabetic wounds focusing on impaired angiogenesis, neuropathy, sub-optimal chronic inflammatory response, barrier disruption, and subsequent polymicrobial infection, followed by current and future treatment strategies designed to tackle the various pathologies associated with diabetic wounds. Given the alarming increase in the prevalence of diabetes, and subsequently diabetic wounds, it is imperative that future treatment strategies target multiple causes of impaired healing in diabetic wounds.

Itch in diabetes: a common underestimated problem

Introduction

Diabetes mellitus is associated with several skin manifestations, however the association with itch remains unclear.

Aim

To present a detailed literature review in order to analyse the frequency, pathogenesis, and course of itch in diabetes mellitus.

Material and methods

Data were collected from the PubMed and Cochrane databases. Articles were excluded if the populations presented with comorbidities or received treatment with drugs affecting the skin. Also, animal studies, studies with poor methodology and pilot studies were excluded.

Results

Among the 5 original articles included, the epidemiology of itch in diabetes varies from 18.4% to 27.5%. Two main factors are associated with the pathogenesis of itch in diabetes, namely skin xerosis and diabetic polyneuropathy. It is still poorly defined how glycaemic control is associated with generalized itch. No treatment of choice is available; however, topical therapy (emollients) provides significant relief in varying percentages of patients.

Conclusions

The results indicate a benefit of diabetes screening in individuals presenting with chronic itch without primary skin lesions.

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.

No significant relation of proinflammatory slanDCs with uremic pruritus

The pathogenesis of the pruritus associated with chronic kidney disease-(CKD-aP) is not completely understood. Endocrine, metabolic, neuropathic, and inflammatory disorders were suspected to be the origin of CKD-aP. Based on the hypothesis which suggests that deregulated systemic inflammation may play a crucial role in CKD-a, we investigated the potential relation of an inflammatory monocyte subset (slanDCs) with CKD-aP. Itch questionnaire, visual analogue scale (VAS)-scoring, and Dermatology Life Quality Index (DQLI) were applied for the characterization of itch sensation. VAS-scoring was re-evaluated after 6 months. Monocytes were flow-cytometrically categorized into classical, intermediate, and non-classical subsets. slanDCs are part of the non-classical monocyte subpopulation. Sixty-six hemodialysis patients (CKD5-D) were screened of whom 43 met the study inclusion criteria. In all, 46.5% of patients were scored pruritus-positive (CKD-aP+). CKD-aP severity level of patients was moderate at the start of the study (VAS 5.3 ± 2.5) and remained unchanged after 6 months (VAS: 5.2 ± 1.9, P < 0.757). Thirty percent of patients were affected with mild, 30.0% with moderate, and 35.0% with severe itchiness. In contrast to all other factors tested solely slanDC showed a weak correlation to VAS-score (r = 0.41, P = 0.07). slanDC frequencies between CKD5-D patients with and without itch sensation, however, were not significantly different. Endocrine problems appeared to influence CKD-aP. CKD-aP + patients had significantly higher L-thyroxin supplementation than CKD-aP- (50.0% vs 8.7%, P < 0.005). A binary logistic regression model confirmed the significance of L-thyroxin medication on chronic itch problems of our CKD5-D patients ( P < 0.007). There is no clear evidence that slanDCs are related to uremic pruritus. Therefore, other factors underlie the pathophysiology of CKD-aP.

Itching as the onset of pain (part 2)

Itching of the skin is a particularly unpleasant subjective sensation that causes the need to scratch. Physiological itching occurs in response to environmental irritants (friction, insect crawling, temperature changes, etc.) and disappears after elimination of the cause. Pathological itching is caused by changes in the skin or throughout the body and causes a strong need to get rid of itching by combing or any other method. Itching is a common symptom of local (dermatological) or general (systemic) disease. It can be limited (localized) or diffuse (generalized).One of the causes of itching is often noted endocrine diseases and metabolic disorders: hyper- and hypofunction of the thyroid gland, diabetes mellitus and hyperparathyroidism. In thyroid hyperfunction, generalized (inconstant and little-pronounced) itching of the skin is observed in the clinical picture only in 10 % of patients. It is accepted that itching of the skin in thyrotoxicosis syndrome is due to increased activity of kinin in combination with an increase in major metabolism and an increase in body and skin temperature (123).Itching caused by impaired bile secretion is characteristic of many diseases of the liver: primary biliary cirrhosis, sclerosing cholangitis, viral hepatitis caused by cholestasis medications and other causes of obstructive jaundice. It is in these cases that prurigo is usually generalized, but in some typical cases it is more pronounced on the feet and palms. With this pathology, itching is caused by obstruction of the biliary tract, however, and to this day, no close correlation has been found between serum bilirubin and the severity of itching.If it was previously thought that itching in pathology of the peripheral or central nervous system, such as multiple sclerosis, neuropathy, compression or irritation of nerves (e.g., paraesthetic dorsalgia, brachioradial itching) is also a significant symptom, then modern studies prove that in more cases, itching is not characteristic of most pathologies of the nervous system, so after a detailed anamnesis, examination and initial research, the patient should be referred to a related specialist, except in cases of about obvious postherpetic neuropathy, painless paresthesia, or brachioradial itching, which can often be guided in the provision of primary care.Instead, there are some psychological conditions and a number of psychiatric illnesses (obsessive-compulsive disorders, depression, and parasite illusions) that are most commonly diagnosed with the exclusion method. Neurotic squabbles are scattered on the body of the excorii, covered with scales that may occur in any area of the body that the patient may reach, but are often limited by limbs.

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.

Management of Itch in the Elderly: A Review

Chronic itch is common in the elderly patient and may be caused by a variety of known dermatologic and non-dermatologic conditions and can have a significant effect on quality of life. Age-related changes in barrier function, immunosenescence, and neuronal changes and neuropathies are common predisposing factors to chronic itch in this age group. Certain primary dermatologic conditions are more common in the elderly and can cause chronic itch. Also, co-morbid diseases particularly of the renal, hepatobiliary, or hematologic systems, psychologic conditions, or medications may contribute to chronic itch in this population. Thus, medical workup for an elderly patient with chronic itch requires special attention to the patient's medical history, current health status, and medications. Topical treatments and emollients may be recommended for elderly patients, with consideration of specific adverse effects and alternatives. Systemic medications pose a higher risk of adverse effects and many are contraindicated in the elderly for this reason. In addition, management in the elderly may be complicated by differential pharmacokinetics of medications, the presence of co-morbid health conditions, cognitive disorders, physical limitations, and polypharmacy. New and emerging treatment modalities hold promise for use in the elderly due to these special considerations.

[Pruritus in systemic diseases : Common and rare etiologies]

Chronic pruritus is a symptom of various internal disorders. In contrast to dermatological diseases, pruritus does not present with primary skin alterations in these patients. However, intense scratching my cause secondary skin changes such as abrasion, excoriation, prurigo nodularis, or in rare cases even scarring. The most common internal causes for chronic pruritus are chronic kidney disease, hepatobiliary, and hematological disorders as well as adverse drug reactions. Pruritus is less commonly seen in patients with endocrine or metabolic diseases, malabsorption syndromes, infectious diseases, and solid tumors. The pathogenesis of pruritus in these disorders remains largely elusive, albeit first insights have been gained for uremic and cholestatic pruritus. Antipruritic treatment is therefore symptomatic in most cases and may represent a clinical challenge. The calcium channel blockers gabapentin and pregabalin have the best proven efficacy in chronic kidney disease associated pruritus. In Japan, nalfurafine, a κ-opioid receptor agonist, has been licensed for this indication. UVB light may also attenuate uremic symptoms. In patients suffering from hepatobiliary disorders the sequestrant cholestyramine and the enzyme inducer rifampicin are effective. Furthermore, bezafibrate, the μ‑opioid receptor antagonists and, in Japan, nalfurafine may be used to ameliorate cholestatic pruritus. So far, no randomized controlled trials have been performed for chronic itch in other internal disorders. Antipruritic treatment is symptom-based with a focus on the effective therapy of the underlying disease.

Evaluation of Chronic Pruritus in Patients over Age 65 Who Admitted to Family Medicine Outpatient Clinic

Aim: This study aims to evaluate the hematologic values, multiple drug use, regions with pruritus, number of regions with pruritus, and systematic diseases of patients over age 65 with chronic pruritus. Methods: A detailed evaluation was made of the hematologic values, itchy regions, multiple drug use, and systematic diseases of 102 patients age 65 and older who presented to our Family Health Center within the past year. Results: When the patients were evaluated according to additional disease, 39 (38.2%) patients had one, and 63 (61.8%) patients had more than one additional disease. According to drug use, 36 (35.5%) patients were using one drug, 27 (26.5%) were using two different drugs, and 39 (38.2%) patients were using three or more different drugs. Number of itchy regions was found to have no significant impact on number of additional diseases. There was no significant difference in number of itchy regions according to number of different drugs used. Conclusion: A detailed hematologic, systematic disease, and multiple drug use assessment of patients ages 65 and older who presenting with chronic itching to Family Health centers could establish a general approach to elderly individuals with chronic pruritus.

The role of Nav1.7 and methylglyoxal-mediated activation of TRPA1 in itch and hypoalgesia in a murine model of type 1 diabetes

Methylglyoxal (MGO), an endogenous reactive carbonyl compound, plays a key role in the pathogenesis of diabetic neuropathy. The aim of this study is to investigate the role of MGO in diabetic itch and hypoalgesia, two common symptoms associated with diabetic neuropathy.

Methods: Scratching behavior, mechanical itch (alloknesis), and thermal hypoalgesia were quantified after intradermal (i.d.) injection of MGO in naïve mice or in diabetic mice induced by intraperitoneal (i.p.) injection of streptozotocin (STZ). Behavioral testing, patch-clamp recording, transgenic mice, and gene expression analysis were used to investigate the mechanisms underlying diabetic itch and hypoalgesia in mice.

Results: I.d. injection of MGO evoked dose-dependent scratching in normal mice. Addition of MGO directly activated transient receptor potential ankyrin 1 (TRPA1) to induce inward currents and calcium influx in dorsal root ganglia (DRG) neurons or in TRPA1-expressing HEK293 cells. Mechanical itch, but not spontaneous itch was developed in STZ-induced diabetic mice. Genetic ablation of Trpa1 (Trpa1^-/-), pharmacological blockade of TRPA1 and Na_v1.7, antioxidants, and mitogen-activated protein kinase kinase enzyme (MEK) inhibitor U0126 abrogated itch induced by MGO or in STZ-induced diabetic mice. Thermal hypoalgesia was induced by intrathecal (i.t.) injection of MGO or in STZ-induced diabetic mice, which was abolished by MGO scavengers, intrathecal injection of TRPA1 blockers, and in Trpa1^-/-mice.

Conclusion: This study revealed that Na_v1.7 and MGO-mediated activation of TRPA1 play key roles in itch and hypoalgesia in a murine model of type 1 diabetes. Thereby, we provide a novel potential therapeutic strategy for the treatment of itch and hypoalgesia induced by diabetic neuropathy.

Clinical presentation, management, and pathophysiology of neuropathic itch

Unlike conventional itch, neuropathic itch develops in normal skin from excess peripheral firing or dampened central inhibition of itch pathway neurons. Neuropathic itch is a symptom of the same central and peripheral nervous system disorders that cause neuropathic pain, such as sensory polyneuropathy, radiculopathy, herpes zoster, stroke, or multiple sclerosis, and lesion location affects symptoms more than aetiology. The causes of neuropathic itch are heterogeneous, and thus diagnosis is based primarily on recognising characteristic, disease-specific clinical presentations. However, the diagnosis of neuropathic itch is challenging, different subforms exist (eg, focal vs widespread, peripheral vs central), and the mechanisms of neuropathic itch are poorly understood, resulting in reduced treatment availability. Currently available strategies include treating or preventing causal diseases, such as diabetes or herpes zoster, and topical or systemic medications that calm excess neuronal firing. Discovery of itch mediators such as gastrin releasing peptide, receptors (eg, neurokinin-1), and pathways (eg, Janus kinases) might encourage much needed new research into targeted treatments of neuropathic itch.

Causes, pathophysiology, and treatment of pruritus in the mature patient

Chronic itch is a common and debilitating health condition in the elderly. There are several common causes of itch in the mature population, such as skin xerosis, immunosenescence, and neuropathic changes. In addition, skin diseases, such as seborrheic dermatitis and stasis dermatitis, systemic conditions (end-stage renal disease and diabetes), or psychogenic derailments, such as depression, anxiety, and dementia, can all serve as triggers of pruritus. Polypharmacy, a common occurrence among the elderly population, may also serve as a cause of itch that may or may not be accompanied by dermatitis. Such medications as μ opioids and calcium channel blockers have been found to have a connection with pruritus in the advanced aging population. Determining the exact trigger for pruritus in the elderly may be especially challenging, because itch can be idiopathic in many cases. The role of treatments should not only take into account elimination of various underlying cutaneous, systemic, or psychogenic conditions associated with itch but also focus on the skin changes that are characteristic of the aging process. Development of such treatment options can be guided by elucidation of the mechanisms underlying the pathophysiology of itch in the geriatric population.

TNF-α/TNFR1 Signaling is Required for the Full Expression of Acute and Chronic Itch in Mice via Peripheral and Central Mechanisms

Increasing evidence suggests that cytokines and chemokines play crucial roles in chronic itch. In the present study, we evaluated the roles of tumor necrosis factor-alpha (TNF-α) and its receptors TNF receptor subtype-1 (TNFR1) and TNFR2 in acute and chronic itch in mice. Compared to wild-type (WT) mice, TNFR1-knockout (TNFR1-KO) and TNFR1/R2 double-KO (DKO), but not TNFR2-KO mice, exhibited reduced acute itch induced by compound 48/80 and chloroquine (CQ). Application of the TNF-synthesis inhibitor thalidomide and the TNF-α antagonist etanercept dose-dependently suppressed acute itch. Intradermal injection of TNF-α was not sufficient to evoke scratching, but potentiated itch induced by compound 48/80, but not CQ. In addition, compound 48/80 induced TNF-α mRNA expression in the skin, while CQ induced its expression in the dorsal root ganglia (DRG) and spinal cord. Furthermore, chronic itch induced by dry skin was reduced by administration of thalidomide and etanercept and in TNFR1/R2 DKO mice. Dry skin induced TNF-α expression in the skin, DRG, and spinal cord and TNFR1 expression only in the spinal cord. Thus, our findings suggest that TNF-α/TNFR1 signaling is required for the full expression of acute and chronic itch via peripheral and central mechanisms, and targeting TNFR1 may be beneficial for chronic itch treatment.

[Pruritus in systemic diseases : Common and rare etiologies]

Chronic pruritus is a symptom of various internal disorders. In contrast to dermatological diseases, pruritus does not present with primary skin alterations in these patients. However, intense scratching may cause secondary skin changes such as abrasion, excoriation, prurigo nodularis, or in rare cases even scaring. The most common internal medicine causes for chronic pruritus are chronic kidney disease, hepatobiliary and hematological disorders as well as adverse drug reactions. Pruritus is less commonly seen in patients with endocrine or metabolic diseases, malabsorption syndromes, infectious diseases and solid tumors. The pathogenesis of pruritus in these disorders remains largely elusive, albeit preliminary insights have been gained for uremic and cholestatic pruritus. Antipruritic treatment is therefore symptomatic in most cases and may represent a clinical challenge. The calcium channel blockers gabapentin and pregabalin have the best proven efficacy in chronic kidney disease-associated pruritus. In Japan nalfurafine, a κ-opioid receptor agonist, has been licensed for this indication. UVB light may also attenuate uremic symptoms. In patients suffering from hepatobiliary disorders the sequestrant cholestyramine and the enzyme inducer rifampicin are effective. Furthermore, μ‑opioid receptor antagonists and sertraline may be used to ameliorate cholestatic pruritus. So far, no randomized controlled trials have been performed for chronic itch in other internal medicine disorders. Antipruritic treatment is mainly based on effective therapy of the underlying disease.

Intraepidermal Nerve Fiber Density: Diagnostic and Therapeutic Relevance in the Management of Chronic Pruritus: a Review

In recent years, measurement of the intraepidermal nerve fiber (IENF) density has gained relevance in the diagnostics of chronic pruritus. This method allows the objectification and quantification of a small-fiber neuropathy, which may manifest clinically with pruritus, pain or dysesthetic sensory symptoms, such as burning, stinging and tingling sensations or numbness. Upon suspicion of a small-fiber neuropathy as a cause for chronic pruritus, targeted diagnostic procedures are essential for the early detection of the neuroanatomical changes. After a punch biopsy of the lower leg, the obtained tissue undergoes an immunofluorescence staining process with a primary antibody against the protein gene product 9.5. The IENFs can thus be detected and are quantified according to pre-determined guidelines based on an international consensus. In addition to morphological changes, functional impairment of small-fibers can be assessed using quantitative sensory testing by assessing detection and pain thresholds of various thermal and mechanic modalities. This method, however, is time-consuming and requires a specialized investigator, and thus it is not routinely used in the diagnostic investigation of chronic pruritus. Diagnosing a small-fiber neuropathy underlying chronic pruritus has therapeutic relevance. If possible, the underlying cause of the neuropathy should be treated. Alternatively, symptomatic therapy options include topical (capsaicin) and systemic (anticonvulsants and/or antidepressants) agents. Chronification processes may lead to refractory pruritus, and thus treatment should be initiated as soon as possible. The aim of this review is to present and discuss the measurement of the IENF density as a diagnostic tool and its role in the management of patients with chronic pruritus. A brief case report is presented to better illustrate the role of this diagnostic method in the clinical setting.

Antioxidants Attenuate Acute and Chronic Itch: Peripheral and Central Mechanisms of Oxidative Stress in Pruritus

Itch (pruritus) is one of the most disabling syndromes in patients suffering from skin, liver, or kidney diseases. Our previous study highlighted a key role of oxidative stress in acute itch. Here, we evaluated the effects of antioxidants in mouse models of acute and chronic itch and explored the potential mechanisms. The effects of systemic administration of the antioxidants N-acetyl-L-cysteine (NAC) and N-tert-butyl-α-phenylnitrone (PBN) were determined by behavioral tests in mouse models of acute itch induced by compound 48/80 or chloroquine, and chronic itch by treatment with a mixture of acetone-diethyl-ether-water. We found that systemic administration of NAC or PBN significantly alleviated compound 48/80- and chloroquine-induced acute itch in a dose-dependent manner, attenuated dry skin-induced chronic itch, and suppressed oxidative stress in the affected skin. Antioxidants significantly decreased the accumulation of intracellular reactive oxygen species directly induced by compound 48/80 and chloroquine in the cultured dorsal root ganglia-derived cell line ND7-23. Finally, the antioxidants remarkably inhibited the compound 48/80-induced phosphorylation of extracellular signal-regulated kinase in the spinal cord. These results indicated that oxidative stress plays a critical role in acute and chronic itch in the periphery and spinal cord and antioxidant treatment may be a promising strategy for anti-itch therapy.

Diabetes mellitus and the skin

Diabetes is a debilitating, life-threatening disease accounting in 2015 for the death of 5 million people worldwide. According to new estimations, 415 million adults currently suffer from the disease, and this number is expected to rise to 642 million by 2040. High glucose blood levels also affect the skin among systemic organs, and skin disorders can often predict the onset of this metabolic disorder. In this review, we address the pathomechanistic effects of diabetes on the skin and give an overview on the most common skin diseases associated with diabetes.

Chronic pruritus in the elderly: pathophysiology, diagnosis and management

Chronic itch in the elderly is a common problem, with a significant impact on quality of life and sleep in elderly patients. Chronic itch may be attributable to several causes, including dry skin, immunosenescence and neural degeneration. Itch may also be caused by skin diseases, such as seborrhoeic dermatitis and stasis dermatitis; systemic conditions, such as end-stage renal disease and diabetes; and psychogenic conditions, such as depression and anxiety. The use of polypharmacy may also cause itch, with or without a rash. Specifically, thiazides and calcium channel blockers have been known to cause itch in elderly patients. Management should be tailored according to the underlying dermatological or systemic aetiology of itch. Topical treatment is the mainstay of therapy, providing special emphasis on skin hydration and barrier repair. In addition, topical and oral medications that target the nervous system and reduce neuronal hypersensitization, such as gabapentin and selective antidepressants, have a role in treating patients with severe chronic itch. Furthermore, management must account for changes in metabolism and pharmacokinetics of drugs in the aging population in order to prevent the occurrence of adverse effects.

Association of systemic diseases with cutaneous dermatosis in elderly population: preliminary observation at a rural tertiary care centre

Introduction:

Aging population is susceptible to many cutaneous and systemic diseases, simultaneously leading to impairment of quality of life in them.

Aim:

To know the association of dermatosis and systemic diseases in geriatric age group.

Materials and Methods:

A retrospective study was carried on patients above 60 years of age who visited the Dermatology OPD at rural tertiary care centre from June 2009 to May 2010. Patients were assessed on a prescribed 30 point proforma.

Results:

Total 457 geriatric patients with dermatosis were registered under the study, of these 203 patients had one or more systemic diseases. Hypertension (70.9%) was the commonest disease, followed by diabetes (32.5%). Eczema was commonest dermatosis in patients with hypertension and generalized pruritus in diabetes.

Conclusion:

Skin diseases cause considerable morbidity in elderly, particularly if associated with other comorbid conditions, so health promotion and education can do much to reduce the risk.

Itch control by Toll-like receptors

Toll-like receptors (TLRs) are cellular sensors designed to recognize molecular danger signals associated with exogenous or endogenous threats. Their activation leads to initiation of the host's immune responses in order to remove or contain the danger. However, one of the most effective methods of defense against invading pathogens and parasites is itch. The perception of itch elicits the rapid defensive action to scratch, which can remove the offending pathogen or parasite before infection can occur. Recent findings show that TLRs such as TLR3, TLR4, and TLR7 are expressed in a subset of pruriceptive/nociceptive neurons in the dorsal root and trigeminal ganglion providing a direct link between TLR activation and itch. Activation of neuronal TLRs can initiate itch sensation by coupling with ion channels. Furthermore, TLRs are expressed in skin cells and glial cells in the spinal cord to regulate inflammation and neuroinflammation in chronic itch. Thus, identification of the role of TLRs in neurons, skin cells, and glial cells may provide new targets for the treatment of chronic itch, a common clinical problem associated with skin diseases, systemic diseases, and metabolic disorders, for which current treatments are far from sufficient.

Advanced aging skin and itch: addressing an unmet need

Itch is the most common skin disorder in the elderly and frequently diminishes quality of life in this population. The high prevalence of pruritus in elderly patients is attributed in part to the decline in the normal physiology of the advanced aging skin, and reflects poor hydration, impaired skin barrier, and altered neural function, all ultimately contributing to inflammation and pruritus. As the elderly population continues to grow, practitioners need to be aware of how to evaluate and manage pruritus, recognizing the common conditions contributing to itch in elderly patients as well as the challenges of treatment in this group. Ultimately, management of pruritus will require an individually tailored approach that is guided by a patient's general health, severity of symptoms, and the potential adverse effects of itch therapies.

Transient receptor potential ankyrin 1 (TRPA1) ion channel in the pathophysiology of peripheral diabetic neuropathy

Background

Transient receptor potential ankyrin 1 (TRPA1) is a non-selective cation channel permeable to calcium that is expressed on pain-mediating primary afferent nerve fibers. Here we review recent experimental evidence supporting the hypothesis that activation of the TRPA1 channel by reactive compounds generated in diabetes mellitus, such as 4-hydroxynonenal and methylglyoxal, exerts an important role in the pathophysiology of peripheral diabetic neuropathy (PDN). The hypothesis includes development of the early diabetic pain hypersensitivity and the later loss of cutaneous nerve endings of pain fibers and their dysfunction, which are hallmarks of peripheral diabetic neuropathy (PDN).

Methods

The evidence for a role of the TRPA1 channel in PDN consists of in vitro patch clamp and calcium imaging data and assessments of pain behavior, axon reflex measurements, and immunohistochemical analyses of cutaneous innervation in an experimental animal model of diabetes. The experiments were combined with blocking the TRPA1 channel with selective antagonists Chembridge-5861528 or A-967079.

Results

In vitro studies indicate that under physiological concentration of Ca2+, methylglyoxal and 4-hydroxynonenal produce sustained activation of the TRPA1 channel and sustained inflow of calcium. In vivo studies indicate that diabetic pain hypersensitivity is maintained by the TRPA1 channel as indicated by the antihypersensitivity effect induced by acute blocking of the TRPA1 channel. Moreover, TRPA1 channel is involved in the development of diabetic hypersensitivity as indicated by prevention of the development of pain hypersensitivity in diabetic animals treated daily with Chembridge-5861528. The diabetes-induced loss of substance P-like cutaneous innervation and that of the TRPA1 channel-mediated cutaneous axon reflex function during the later phase of diabetes were also prevented or delayed by prolonged blocking of the TRPA1 channel. No motor impairment or other obvious side-effects were observed following block of the TRPA1 channel.

Conclusions

Together the in vitro and in vivo results indicate that reactive compounds generated in diabetes exert, through action on the TRPA1 channel, an important role in the pathophysiology of PDN. Sustained activation of the TRPA1 channel is a plausible mechanism that contributes to the early diabetic pain hypersensitivity and the later loss of cutaneous pain fiber endings and their dysfunction with prolonged diabetes.

Implications

Blocking the TRPA1 channel with a selective antagonist provides a promising disease-modifying treatment for PDN, with only minor, if any, side-effects.

Role of prostaglandin D2 and the autonomic nervous system in niacin-induced flushing

BACKGROUND

Although niacin often has beneficial effects on the lipoprotein profile, flushing is an untoward effect associated with its use. Aspirin can only reduce the flushing response by 30-40%. Thus, the aim of the present study was to investigate the mechanisms of niacin-induced flushing, with and without aspirin, in normal, healthy individuals.

METHODS

Niacin-induced flushing was evaluated in 30 healthy individuals after oral administration of 1000 mg niacin alone or with 325 mg aspirin. Neurological, autonomic nervous system, and skin blood flow measurements (using laser Doppler on the glabrous and hairy skin of each participant) were made at various times after drug administration. In addition, the systemic release of 9α,11β-prostaglandin (PG) F(2) was determined. Flushing symptoms of redness, warmth, tingling, itching, and intensity were recorded using the modified Flushing ASsessment Tool (FAST).

RESULTS

After aspirin, the mean flushing scores for all symptoms decreased significantly; however, 36-53% of participants still had some degree of symptoms, even though aspirin completely blocked 11β-PGF(2) synthesis. Maximum skin blood flow (MaxSkBF) in both the glabrous and hairy forearm increased significantly after niacin, but decreased significantly after aspirin only in hairy skin. Regression analysis showed that, in glabrous skin, both PGF(2) and parasympathetic activity were significant predictors of MaxSkBF after niacin, contributing 26% and 14%, respectively (total R(2) = 40%).

CONCLUSIONS

The present study indicates, for the first time, that the parasympathetic nervous system, in addition to PGD(2) , may play an important role in niacin-induced flushing. Changing the sympathetic/parasympathetic balance in favor of parasympathetic activation may be a good therapeutic target to reduce niacin-induced flushing.

Emerging role of Toll-like receptors in the control of pain and itch

Toll-like receptors (TLRs) are germline-encoded pattern-recognition receptors that initiate innate immune responses by recognizing molecular structures shared by a wide range of pathogens, known as pathogen-associated molecular patterns (PAMPs). After tissue injury or cellular stress, TLRs also detect endogenous ligands known as danger-associated molecular patterns (DAMPs). TLRs are expressed in both non-neuronal and neuronal cell types in the central nervous system (CNS) and contribute to both infectious and non-infectious disorders in the CNS. Following tissue insult and nerve injury, TLRs (such as TLR2, TLR3, and TLR4) induce the activation of microglia and astrocytes and the production of the proinflammatory cytokines in the spinal cord, leading to the development and maintenance of inflammatory pain and neuropathic pain. In particular, primary sensory neurons, such as nociceptors, express TLRs (e.g., TLR4 and TLR7) to sense exogenous PAMPs and endogenous DAMPs released after tissue injury and cellular stress. These neuronal TLRs are new players in the processing of pain and itch by increasing the excitability of primary sensory neurons. Given the prevalence of chronic pain and itch and the suffering of affected people, insights into TLR signaling in the nervous system will open a new avenue for the management of clinical pain and itch.

Oxidative stress induces itch via activation of transient receptor potential subtype ankyrin 1 in mice

OBJECTIVE

To investigate the role of oxidative stress in itch-indicative scratching behavior in mice, and furthermore, to define the cellular and molecular mechanisms underlying oxidative stress-mediated itch.

METHODS

Scratching behavior was induced by intradermal injection of the oxidants hydrogen peroxide (H₂O₂) or tert-butylhydroperoxide (tBHP) into the nape of the neck in mice. The mice were observed for 30 min.

RESULTS

Intradermal H₂O₂ (0.03%-1%) or tBHP (1-30 μmol) elicited robust scratching behavior, displaying an inverted U-shaped dose-response curve. Naloxone, an opioid receptor antagonist, but not morphine, largely suppressed the oxidant-induced scratching. Chlorpheniramine, a histamine H1 receptor antagonist, blocked histamine- but not oxidant-induced scratching, indicating the involvement of a histamine-independent mechanism in oxidant-evoked itch. Further, resiniferatoxin treatment abolished oxidant-induced scratching, suggesting an essential role of C-fibers. Notably, blockade of transient receptor potential subtype ankyrin 1 (TRPA1) with the selective TRPA1 antagonist HC-030031, or genetic deletion of Trpa1 but not Trpv1 (subfamily V, member 1) resulted in a profound reduction in H₂O₂-evoked scratching. Finally, systemic administration of the antioxidant N-acetyl-L-cysteine or trolox (a water-soluble vitamin E analog) attenuated scratching induced by the oxidants.

CONCLUSION

Oxidative stress by different oxidants induces profound scratching behavior, which is largely histamine- and TRPV1-independent but TRPA1-dependent. Antioxidants and TRPA1 antagonists may be used to treat human itch conditions associated with oxidative stress.

[Pain and pruritus : differences and similarities as revealed by the PainDetect questionnaire parameters]

Chronic pruritus and chronic pain are frequent symptoms of a variety of underlying diseases. Painful sensations usually suppress acute itching. In chronic states, both may be present in parallel and be a part of one event. Patients with chronic pruritus should be asked for the presence of pain, which can be identified and characterized using specific and validated questionnaires. The early detection of (neuropathic) pain in patients with chronic pruritus can be done using the PainDetect questionnaire. In general, patients suffering from both itch and pain have a highly impaired quality of life, high degree of objective health burden, need a more intensive health care and a complex analgetic and antipruritic therapy.

Skin signs in diabetes mellitus

Diabetes mellitus is the most common endocrine disorder with continuously increasing prevalence. Blood vessels, nerves, eyes, kidneys and skin are affected, which causes both an enormous financial burden and a reduced quality of life of the affected patients. Long-standing diabetes may impair skin homeostasis resulting in skin manifestations in at least one third of all diabetics. The skin involvement may be the first presenting sign of diabetes, thus the respective skin signs should lead to diabetes focused diagnostic. Besides, the skin signs may be considered as a marker for the course of the disease or for the success of therapeutic interventions.