Methotrexate for refractory adult atopic dermatitis leads to alterations in cutaneous IL-31 and IL-31RA expression

Abstract Background: Methotrexate (MTX) is an alternative treatment for patients with moderate/severe atopic dermatitis (AD). Objective: The authors evaluated the effect of MTX on the cutaneous expression of cytokines and chemokines that are involved in the inflammatory response in adult AD patients who received treatment with methotrexate for 24 weeks. Methods: The authors conducted a prospective single-institution cohort study with 12 adults with moderate/severe AD who received oral MTX (15 mg/wk for 24 wks) and 10 non-atopic matched controls. The comparison was made of skin biopsies of lesional and non-lesional skin, pre- and post MTX treatment. The authors analyzed mean epidermal thickness and expression of IL-31, IL-31RA, OSMR, TSLP, Ki67, IL-4 mRNA, IL-6, IL-10, TNF-α, IFN-γ, TARC, and CCL-22. Results: There was a reduction in mean epidermal thickness (p = 0.021), an increase in IL-31RA expression (immunohistochemistry) in the epidermis (p = 0.016) and a decrease in IL-31 gene expression (p = 0.019) on lesional AD skin post-MTX treatment. No significant changes in the cutaneous expression of the other evaluated markers were identified. Study limitations: Small sample size and limited length of follow-up. Conclusions: Treatment with MTX in adults with moderate/severe AD reduced epidermal hyperplasia and changed the cutaneous expression of inflammatory cytokines and receptors that are mainly related to pruritus, including IL-31 and IL-31RA.

Manifestaciones dermatológicas de la cirrosis hepática: revisión de la literatura / Dermatological manifestations of liver cirrhosis: review of the literature

La piel y sus anexos tienen amplia relación con todos los órganos y sistemas. Los cambios presentes en estos pueden ser el primer hallazgo en un paciente con enfermedad hepática, encontrándose hasta en el 20 % de los casos, por lo que las manifestaciones extrahepáticas adquieren importancia, y aunque muchas de estas no son específicas, algunos marcadores dermatológicos pueden ayudar al diagnóstico de la enfermedad y se pueden correlacionar con su severidad. El desarrollo de las lesiones cutáneas en los pacientes con cirrosis hepática se genera principalmente por hipertensión portal y exceso de estrógenos circulantes, por lo tanto, su tratamiento se basa en el manejo de la patología hepática subyacente. En el presente artículo se hace una revisión de la literatura y se describe un amplio espectro de manifestaciones dermatológicas asociadas a cirrosis hepática, con sus características y etiopatogénesis, siendo las más frecuentes la ictericia, el prurito, los nevus en araña, el eritema palmar, las venas en cabeza de Medusa, y los cambios de uñas y del vello, entre otras.

The skin and its annexes have a broad relationship with all organs and systems. Changes present in these can be the initial finding in a patient with liver disease, occurring in up to 20% of cases, therefore the extrahepatic manifestations become important, and although many of these are not specific, some dermatological markers can help in the diagnosis of the disease and may correlate with its severity. The development of cutaneous lesions in patients with liver cirrhosis is mainly generated by portal hypertension and excess of circulating estrogens, therefore their treatment is based on managing the underlying liver pathology. This article reviews the literature and describes a wide range of dermatological manifestations associated with liver cirrhosis, with their characteristics and etiopathogenesis, being the most frequent jaundice, pruritus, spider nevus, palmar erythema, caput Medusae veins, nail and hair changes, among others.

Manifestaciones cutáneas comunes de las principales enfermedades hepáticas / Common cutaneous manifestations of major liver diseases

Las enfermedades hepáticas presentan múltiples manifestaciones sistémicas, entre las cuales se destacan los hallazgos en piel, siendo los más comunes el prurito y la ictericia; así mismo, se pueden encontrar angiomas en araña, eritema palmar, xantomas, vasculitis y cambios en anexos. Este artículo tiene como objetivo describir los principales signos y síntomas cutáneos en las enfermedades hepáticas para brindar herramientas semiológicas al clínico en su práctica diaria

Liver disease present multiple systemic manifestations, among which skin findings stand out, being the most common pruritus and jaundice. Other findings can also be manifested like spider angiomas, palmar erythema, xanthomas, vasculitis and changes in skin appendages. The objective of this article is to describe the main skin signs and symptoms of liver diseases to provide semiological tools to the physician in his daily practice.

Can chronic spontaneous urticarial produce symptoms of neuropathic pain?

Abstract Background Chronic spontaneous urticaria (CSU) is a condition that is associated with recurrent pruritic hives and/or angioedema lasting for more than 6 weeks and is known to affect 1% of the population. Neuropathic pain can be defined as abnormal pain in the peripheral or central nervous system following injury and results from dysfunctions in the peripheral or central nervous system without peripheral nociceptor stimulation. Histamine appears in the pathogenesis of both the CSU and diseases of the neuropathic pain spectrum. Objective To evaluate the symptoms of neuropathic pain in patients with CSU using scales. Method Fifty-one patients with CSU and 47 sex- and age-matched healthy controls were included in the study. Results The results of the short-form McGill Pain Questionnaire revealed the scores in the sensory and affective domains, Visual Analogue Scale (VAS) scores and pain indices to be significantly higher in the patient group (p < 0.05 for all cases), while the overall pain assessment and sensory assessment based on the Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS) pain scale were also significantly higher in the patient group. Based on the assumption that scores of > 12 indicated neuropathy, 27 (53%) of the patients in the patient group and 8 (17%) in the control group were found to have neuropathy (p < 0.05). Study limitations Cross-sectional study, small patient sample and use of self-reported scales. Conclusion In addition to itching, patients with CSU should be aware of the potential for the association of neuropathic pain. In this chronic disease that is known to affect the quality of life, using an integrated approach with the patients and identifying accompanying problems are as important as treating the dermatological disorder.

Manejo Clínico ­ Quirúrgico de pacientes con Fisura Anal en la Unidad de Coloproctología del HECAM / Clinical-Surgical Management of patients with Anal Fissure in the Unit HECAM Coloproctology

La fisura anal es una de las enfermedades más antiguamente descritas, la misma que, ha tenido hasta el momento múltiples tratamientos tanto médicos como quirúrgicos, existiendo controversias en su algoritmo terapéutico. Constituye una de las patologías cuyo diagnóstico y tratamiento corresponde a la Especialidad de Coloproctología, afecta a ambos sexos y a cualquier edad y puede ser aguda o crónica. Proponemos el presente Protocolo para un adecuado manejo de la patología, de manera que sirva de guía en la toma correcta de decisiones basadas en la evidencia y el consenso de quienes integramos la Unidad Técnica de Coloproctología del Hospital de Especialidades Carlos Andrade Marín.

Anal fissure is one of the oldest described diseases, which has so far had multiple medical and surgical treatments, with controversies in its therapeutic algorithm. It is one of the pathologies whose diagnosis and treatment corresponds to the Coloproctology Specialty, it affects both sexes and any age and can be acute or chronic. We propose the present Protocol for an adequate management of the pathology, so that it serves as a guide in the correct decision making based on evidence and consensus of those who integrate the Technical Unit of Coloproctology of the Hospital de Especialidades Carlos Andrade Marín.

Dermatological manifestations of hematologic neoplasms. Part II: nonspecific skin lesions/paraneoplastic diseases

Abstract Cutaneous manifestations occur in the course of hematologic malignancies and precede, accompany or occur late in relation to the diagnosis. They result from paraneoplastic phenomena, tumor infiltrations, immunosuppression resulting from the hematologic disease itself or its treatment. The dermatologist must be aware of these conditions that may be helpful both in the diagnosis of the underlying disease and in reducing patient morbidity. This review (part II) addresses the paraneoplastic dermatological changes associated with systemic hematologic malignancies.

The role of thermosensitive transient receptor potential vanilloid channel in the dissimilation of itching sensitized by warm in atopic dermatitis / 中国医师杂志

Atopic dermatitis (AD) is an inflammatory skin disease characterized by itch. Transient receptor potential vanilloid (TRPV) receptor subtype channel can be activated by different ranges of harmless temperature, and plays an important role in the warm itching in AD. Inhibitors of TRPV channel can alleviate the symptoms of AD, and may be used as a new target for treatment. This paper introduces the role of thermosensitive TRPV channel in the alienation of itching sensitized by warm in AD.

Clinical study of acupuncture combined with medication in the treatment of skin pruritus in maintenance hemodialysis patients / 针灸推拿医学（英文版）

Objective:To observe the clinical effect of acupuncture combined with Western medicine in the treatment of skin pruritus in maintenance hemodialysis patients.Methods:Eighty patients were randomly divided into a control group and an observation group,with 40 cases in each group.The control group was given loratadine orally,and the observation group was given acupuncture treatment in addition to the treatment used in the control group.The four-item itch questionnaire(FIIQ)score,indicators for skin barrier function,and serum interleukin(IL)-2 and IL-31 levels were compared.The efficacy was judged after the treatment ended.Results:The total effective rate was higher in the observation group than in the control group(P<0.05).After treatment,the site,frequency,severity of pruritus,sleep impact sub-scores,and FIIQ total score in both groups were reduced compared with those before treatment(P<0.05),and all scores in the observation group were lower than those in the control group(P<0.05).The stratum corneum hydration(SCH)and transepidermal water loss(TEWL)in the V-shaped area of the chest,the flexor side of the forearm,and the extensor side of the lower leg were not significantly changed in the control group(P>0.05);the SCH and TEWL in the V-shaped area of the chest,the flexor side of the forearm,and the extensor side of the lower leg in the observation group were improved(P<0.05),and all were better than those in the control group(P<0.05).The serum IL-2 and IL-31 levels in the control group did not change significantly(P>0.05);the serum IL-2 and IL-31 levels in the observation group were both significantly decreased(P<0.05)and were lower than those in the control group(P<0.05).Conclusion:Acupuncture combined with loratadine is highly effective in the treatment of pruritus in maintenance hemodialysis patients,and it can relieve pruritus,improve skin barrier function,and reduce serum IL-2 and IL-31 levels.

Perianal psoriasis as the first manifestation of the disease

Introduction: Inverse psoriasis affects the skin of flexural areas, such as the groin, axillae, umbilicus, intergluteal fold, and external genitalia. Clinical Case: We herein report the case of a man who presented with anal pruritus and, upon physical examination, a perianal dermatosis was found, which was characterized by erythematous plaques, with fine scaling. The case was initially managed with zinc oxide, and when no improvement was observed, we decided to take an incisional biopsy, which indicated histological changes suggestive of psoriasiform dermatitis. Discussion: Inverse psoriasis affects 3% to 7% of patients with psoriasis, and it manifests with erythematous plaques without the classic scaling appearance. The skin in these areas is susceptible to maceration, irritation, and ulceration, which alter the classic clinical picture. It may present with typical lesions or, less frequently, in isolation in the anogenital region. In the anogenital presentation only, the diagnosis should be made by biopsy, looking for the classic histopathological features of psoriasis. As for the first-line treatment, low- or medium-potency topical steroids are used for short periods of time; the second-line treatment is with emollients and tar-based products; and the third-line treatment uses an immunomodulator. Conclusion: This presentation is infrequent, and it requires a high index of suspicion for the diagnosis, always supported by biopsies, in search of the classic histopathological features of psoriasis. (AU)

Kandughna Gana Varti in Vulvo Vaginalcandidiasis - A Case Series

Vulvovaginal candidiasis is an infection caused by yeast like micro organisms called candida albicans. It is the second most common cause of vaginitis affecting women of reproductive age group. It is most distressing and irritating to women, hampers their day to day life and makes them irritable, depressed, anxious and disturbs their interpersonal relationships including marital life. In vulvovaginal candidiasis patients complain of vaginal discharge with intense vulvovaginal pruritus. The pruritus is out of proportion to the discharge. The symptoms of vulvovaginal candidiasis appear similar to the symptoms of Slaishmiki yoni vyapath mentioned in Ayurvedic classics. It is due to the vitiation of Kapha caused by usage of Abishyandi aharas and has symptoms like Pichila yonisrava, Kandu, Alpa vedhana or Avedhana in Yoni. Topical treatments have great importance in the treatment of several gynecological conditions (Yoni vyapaths). Yoni varti or vaginal pessary is used to cleanse the vaginal walls and make the local environment more healthy. It acts directly on the vaginal mucosa and enables easier and target specific action. They are also hygroscopic in property and act in accordance with the drugs they contain. Kandughna gana varti have Tiktha, Kashaya rasa, Laghu, Ruksha guna, Krimighna, Kandughna and Kaphaghna properties and all the ingredients have potent antifungal action also. This facilitates faster absorption of drugs through vaginal mucosa and relieves the symptoms more quickly. A pilot study was conducted in 5 cases to assess the effect of Kandughna gana varti in vulvovaginal candidiasis. It was found to be effective in vaginal discharge and vulvovaginal pruritus.

The Effect of Turbinate Injection of Botulinum Toxin A on the Symptoms of Idiopathic Rhinitis

Abstract Introduction Idiopathic rhinitis is a nonallergic and noninfectious rhinitis characterized mainly by nasal obstruction and rhinorrhea, resulting from an autonomic imbalance. Botulinum toxin type A (BTX-A) demonstrated its action in reducing rhinorrhea and nasal obstruction when injected into the nasal turbinates or septum. Objective To analyze the effects of intranasal BTX-A injection to control the symptoms of idiopathic rhinitis and its possible adverse effects. Method Patients with idiopathic rhinitis were divided into two groups. Group A had 15 participants (8 female and 6 male), of ages from 47 to 84 years (mean 66.57 years), and these received 60 U of Dysport (Ipsen Ltd, Maidenhead, Berkshire, UK) in each inferior nasal turbinate; group B had 12 participants (1 male and 11 female), of ages from 50 to 76 years (mean 60 years), and they received 1 ml of 0.9% saline. The individuals were reevaluated in the 1st, 2nd, 4th, 8th, and 12th weeks after injection by a questionnaire, accompanied by nasal inspiratory peak flow and acoustic rhinometry. Results Group A showed significant improvement, mainly regarding the symptoms of sneezing/itching and nasal obstruction, over time and when compared to group B. Acoustic rhinometry confirmed the improvement in nasal obstruction. There was no relationship between the nasal peak flow data and the nasal obstruction score. No major adverse effects have been reported. Conclusion The injection of botulinum toxin in the inferior nasal turbinates of patients with idiopathic rhinitis reduces the symptoms of sneezing, itching, nasal obstruction, and runny nose without significant adverse effects, suggesting that it is an option in the treatment of these patients.

Spectrum of Skin Manifestations in CKD: A Tertiary Care Center Experience from North India

Introduction: Dermal manifestations in chronic kidney disease (CKD) patients may range from mild ones, like xerosis, skin pallor, pruritus, coated tongue, superficial infections and hair and nail changes, to severe life-threatening ones, like nephrogenic systemic fibrosis, which is a rare entity in current times. The present study was done to evaluate the spectrum of mucocutaneous manifestations in patients with CKD and to look for an association between them and various biochemical parameters and inflammatory markers. Material and methods: This study was a 1 year prospective, observational study conducted on adult patients with CKD who presented to the Nephrology clinic in Pt. BD Sharma PGIMS, Rohtak. Patients between the ages of 17 and 75 years with CKD stages II or more with dermatological conditions were included in this study. Each participant was subjected to detailed clinical, biochemical, radiological and dermatological examination by same consultants in order to avoid interpersonal variations. Various skin, mucosal, nail and hair manifestations along with cutaneous infections were analyzed across the spectrum of CKD. Results: Among cutaneous infections, fungal infections predominated, amongst which, onychomycosis was the most common. Xerosis was the most common dermatological disease and the prevalence of xerosis, skin pallor and pruritus was found to increase significantly from Stage II to Stage V and VD of CKD in a statistically significant manner. An association was found between xerosis and decreasing levels of hemoglobin and while ferritin was not different between patients with and without xerosis, high-sensitivity C-reactive protein (hs-CRP) was significantly higher in patients with xerosis. Similarly, hs-CRP levels were significantly elevated in patients with xerostomia and nail pallor as compared with those who did not have these conditions. Lastly, patients with nail pallor had significantly lower albumin. Conclusion: It was observed in our study that in CKD patients on hemodialysis and on conservative management, xerosis, pruritus, pigmentation, nail changes, oral mucosa changes and cutaneous infections were the predominant cutaneous manifestations. In patients with CKD, mucocutaneous manifestations progressively worsened as renal function deteriorated.

Urticária aquagênica: relato de caso e revisão de literatura / Aquagenic urticaria: a case report and literature review

A urticária aquagênica é uma forma rara de urticária crônica induzida (UCInd) desencadeada por um estímulo específico. A patogênese não é totalmente compreendida, mas os sintomas se iniciam minutos após a exposição cutânea à água, independentemente de sua temperatura, e as urticas têm o padrão foliculocêntricas. O diagnóstico é confirmado através do teste de provocação, e o tratamento de primeira linha são os anti-histamínicos de segunda geração. Neste artigo, relatamos um caso de urticária aquagênica e fazemos uma breve revisão da literatura sobre o tema.

Aquagenic urticaria is a rare form of chronic inducible urticaria (CIndU) triggered by a specific stimulus. Pathogenesis is not fully understood, but symptoms appear minutes after cutaneous exposure to water, regardless of temperature, and wheals have a folliculocentric pattern. The diagnosis of CIndU is confirmed by provocation testing using established protocols, and first-line treatment is second-generation antihistamines. In this article, we report a case of aquagenic urticaria and provide a brief review of the relevant literature.

Efficacy and safety of turmeric 1% emollient cream in the control of chronic kidney disease-associated pruritus in Hemodialysis patients: A randomized double-blind clinical trial

Introduction@#Chronic kidney disease-associated pruritus (CKD-aP) remains a frequent and distressing symptom in hemodialysis patients, fur- ther compromising their quality of life. Turmeric, or Curcuma longa, is a naturally-occurring, widely available product that inhibits major inflamma- tory mechanisms associated with CKD-aP.@*Objectives@#This study aimed to determine the efficacy and safety of turmeric 1% emollient cream versus a bland emollient in the reduction of chronic kidney disease-associated pruritus in hemodialysis patients.@*Methods@#This study was a randomized, double-blind, controlled trial of the effect of turmeric 1% cream in the reduction of chronic kidney disease associated pruritus in hemodialysis patients compared to a bland emollient. The main outcome measure was the proportion of subjects who demonstrated response to treatment, as well as the incidence of adverse effects.@*Results@#Intention to treat analysis on 106 patients, 53 assigned to turmeric 1% cream and 53 to bland emollient cream, was done. There was a sig- nificant difference (P=0.03) in the proportion of patients who achieved treatment success between the turmeric group (66%) and bland emollient group (45%). The mean decrease in pruritus score (VAS) of the group treated with turmeric was significantly greater than that of the bland emol- lient group (P=0.018). No adverse effects were noted in both groups.@*Conclusion@#Among hemodialysis patients diagnosed with CKD-aP, topical application of turmeric 1% cream twice daily for four weeks was supe- rior to that of bland emollient cream based on efficacy and safety outcome measures.

Reduction of serum level of interleukin-2 and pruritus severity after acupuncture at Quchi (LI11) in hemodialysis patients: a placebo-controlled randomized clinical trial / 针灸推拿医学（英文版）

Objective: To observe the effect of acupuncture at Quchi (LI11) on the serum interleukin-2 (IL-2) level and the severity of uremic pruritus (UP) in hemodialysis patients. Methods: Sixty hemodialysis patients with UP were randomized into an acupuncture group and a control group, with 30 cases in each group. In the acupuncture group, patients were treated with acupuncture at Quchi (LI11) twice a week for six weeks. In the control group, each patient received a placebo treatment (sham acupuncture). Before and after the intervention, the pruritis severity was examined using a 5-D scale, and the serum IL-2 level was measured using an enzyme-linked immunosorbent assay kit. Results: There were no statistically significant differences in the demographic or clinical factors between the control group and the acupuncture group at baseline. The reduction in pruritus severity in patients was more significant in the acupuncture group (P=0.027). Acupuncture therapy also significantly decreased the serum IL-2 level in the patients (P=0.011). Throughout the acupuncture procedures, the incidence of pain and mild bleeding was 3.6％ and 2.5％, respectively. Conclusion: Six-week acupuncture treatment at Quchi (LI11) can effectively decrease the severity of UP and the serum IL-2 level. Large-scale, long-duration, and multi-center studies are needed to fully understand the role of IL-2 in inflammation and neuroimmune stimulation during acupuncture.

A case of generalized lichen amyloidosis treated with dupilumab: the first case reported in China / 中华皮肤科杂志

To report a case of generalized lichen amyloidosis successfully treated with dupilumab in China. A 70-year-old male patient presented with extensive itchy papules on the trunk and extremities for 23 years. Skin examination revealed diffuse millet-to mung bean-sized hemispherical brown plaques on the trunk, right anterior shank, and extensor aspect of both upper arms, with a hard texture on palpation. No abnormalities were observed in the blood eosinophil count or serum IgE level. Histopathological examination of the skin lesion on the lower limb showed epidermal hyperkeratosis and homogeneous red-stained lumpy materials in the papillary dermis. Immunohistochemical study showed positive staining with Congo red. The pruritus numerical rating scale score was 10 points. The diagnosis of generalized lichen amyloidosis was confirmed. The patient received subcutaneous injection of dupilumab at an initial dose of 600 mg, followed by an every-2-week regimen at a dose of 300 mg. At week 2 after the start of treatment, pruritus was markedly relieved; at week 14, the skin lesions began to subside markedly; at week 18, the skin lesions on the chest and abdomen nearly completely subsided, and lesions on the lower back and limbs markedly regressed. No obvious adverse reactions were observed.

Mechanisms of pruritus in atopic dermatitis / 中华皮肤科杂志

Pruritus in atopic dermatitis (AD) is typical non-histaminergic itch involving complex nerve pathways. A variety of cytokines and neuropeptides, skin barrier dysfunction and skin microbiome imbalance are also involved in the generation and transmission of itching-relatd signals. This review focuses on main research progress in the pathogenesis and treatment of pruritus in AD in recent years.

Latest research progress on pathological mechanism of senile pruritus / 中华老年医学杂志

The pathological mechanism of the occurrence of elderly pruritus has not yet been fully elucidated.The changes in lipid composition between keratinocytes, incomplete structure of membrane filaggrin, decreased levels of natural moisturizing factors, changes in pH and decreased levels of estrogen can lead to impaired skin barrier function, and play an important role in the pathogenesis of skin pruritus.An inflammatory environment caused by immune aging, and neurological degenerative changes and pathological damage are also believed to influence the occurrence of senile pruritus.In addition, some systemic diseases are also closely related to the occurrence and development of pruritus in the elderly, such as chronic kidney disease, cholestatic diseases, diabetes, malignant tumors, etc.Further elucidation of the pathological mechanism of pruritus in the elderly can provide useful diagnosis and treatment ideas for the prevention and treatment of diseases.

Inhibition of temperature-sensitive TRPV3 channel by two natural isochlorogenic acid isomers for alleviation of dermatitis and chronic pruritus

Genetic gain-of-function mutations of warm temperature-sensitive transient receptor potential vanilloid 3 (TRPV3) channel cause Olmsted syndrome characterized by severe itching and keratoderma, indicating that pharmacological inhibition of TRPV3 may hold promise for therapy of chronic pruritus and skin diseases. However, currently available TRPV3 tool inhibitors are either nonselective or less potent, thus impeding the validation of TRPV3 as therapeutic target. Using whole-cell patch-clamp and single-channel recordings, we report the identification of two natural dicaffeoylquinic acid isomers isochlorogenic acid A (IAA) and isochlorogenic acid B (IAB) that selectively inhibit TRPV3 currents with IC50 values of 2.7 ± 1.3 and 0.9 ± 0.3 μmol/L, respectively, and reduce the channel open probability to 3.7 ± 1.2% and 3.2 ± 1.1% from 26.9 ± 5.5%, respectively. In vivo evaluation confirms that both IAA and IAB significantly reverse the ear swelling of dermatitis and chronic pruritus. Furthermore, the isomer IAB is able to rescue the keratinocyte death induced by TRPV3 agonist carvacrol. Molecular docking combined with site-directed mutations reveals two residues T636 and F666 critical for the binding of the two isomers. Taken together, our identification of isochlorogenic acids A and B that act as specific TRPV3 channel inhibitors and gating modifiers not only provides an essential pharmacological tool for further investigation of the channel pharmacology and pathology, but also holds developmental potential for treatment of dermatitis and chronic pruritus.

Pharmacological action and clinical evaluation of difelikefalin, a new drug for the treatment of uremic pruritus / 中国基层医药

Uremic pruritus is one of the skin complications that perplex patients with end-stage renal disease undergoing hemodialysis or peritoneal dialysis. Because the specific pathogenesis is not clear, there is no unified treatment plan in the world. In August 2021, the US Food and Drug Administration approved the use of difelikefalin (under the trade name Korsuva) for the treatment of moderate to severe pruritus associated with chronic kidney disease in adult patients undergoing hemodialysis. Studies have shown that difelikefalin can remarkably reduce the intensity of pruritus and improve sleep and pruritus-related quality of life. The recommended dose of difelikefalin is 0.5 μg/kg, and difelikefalin is well tolerated and has high safety. This paper reviews the pharmacological effects, pharmacokinetics, clinical efficacy and safety of difelikefalin.