尿毒搔癢症的新進展

Recent Advances in Uremic Pruritus

尿毒性搔癢症是因腎臟功能異常而產生之皮膚搔癢疾患，為末期腎臟病及慢性腎臟病患者最常見的症狀之一。大多數尿毒性搔癢症的患者病程長，且會反覆發作，導致情緒障礙、睡眠不佳、及生活品質下降。尿毒性搔癢症的病理機轉涉及了腎臟、皮膚、免疫和神經多個系統複雜的交互作用。正確診斷、足量透析、妥善的皮膚照護、選擇合適的治療藥物及監測藥物的不良反應，每個環節皆是治療尿毒性搔癢症不可或缺的基石。諸多治療方式中，gabapentinoids，nalfurafine，difelikefaline有最多的臨床試驗支持其療效，可惜的是nalfurafine與difelikefaline至今尚未取得台灣的藥物許可證。此外，紫外線B光光線治療、抗組織胺藥物、活性炭、外用皮質類固醇藥膏、外用辣椒素(capsaicin)藥膏、肥大細胞穩定劑等，leukotriene受體拮抗劑，對某些患者可有效緩解尿毒性搔癢症，但須更多的證據支持其療效及安全性。

Uremic pruritus is a pruritic disorder caused by impaired kidney function. It is one of the most common symptoms in patients with end-stage renal disease and chronic kidney disease. Patients with uremic pruritus have prolonged and relapsing clinical course, resulting in mood disturbance, poor sleep, and impaired quality of life. The pathophysiology of uremic pruritus involves complex multi-system interactions, including kidney, skin, immune and nervous systems. The cornerstones of the management for uremic pruritus are correct diagnosis, optimization of dialysis regimens, appropriate skin care, selection of proper topical and oral medications, and monitoring adverse effects of drugs. Among the treatments, gabapentinoids, nalfurafine, and difelikefalin are the most well studied drugs to support their efficacy. However, nalfurafine, and difelikefalin are not available in Taiwan. In addition, ultraviolet B phototherapy, antihistamines, activated charcoal, topical steroids, topical capsaicin, mast cell stabilizers, and leukotriene receptor antagonists have been reported to be effective in some patients, but more evidence is needed to support their efficacy and safety.