免疫療法的進展，尤其是生物製劑的出現，讓許多皮膚病有了突破性的治療進展。乾癬就是其中 的先行者，目前已有五代不同機轉的生物製劑被核准。除了第一代的alefacept及efalizumab，其他的生物 製劑都仍在臨床使用中，作用於腫瘤壞死因子、介白素12/23、介白素17、介白素23。由於高度療效及 相對良好的安全性，此類產品成為了中重度乾癬患者的黃金治療準則。除乾癬外，dupilumab也剛被核准 用於異位性皮膚炎，這是一種介白素4/13的抑制劑，而IgE抑制劑omalizumab及adalimumab則分別核 准於慢性自發性蓴麻疹及化膿性汗腺炎。最近rituximab則在美國核准用於尋常性天疱瘡。生物製劑雖然 療效佳，相對風險低，但是高昂的費用讓多數需要的患者無法負擔，健保基於財政負擔更無法全面給付。 期待當這些藥品專利過期後，價格下降，能讓更多需要的患者可使用。也期待免疫學的進展，能夠繼續 發現新的藥物及作用機轉，解決更多的皮膚疾病。

Advancement in immunotherapy, especially biologic agents, has revolutionized the treatment of many skin diseases. Psoriasis is at the forefront of this treatment paradigm change. Five generations of biologics have been approved for use in psoriasis. Except for the first generation (alefacept, efalizumab), all the other biologics are still in clinical use targeting tumor necrosis factor, interleukin 12/23, interleukin 17 and interleukin 23. Due to their high efficacy and favorable safety profiles, these biologics have become the gold standard in the treatment of moderate to severe psoriasis. Biologics have also been approved for atopic dermatitis, but only dupilumab, an interleukin 4/13 dual inhibitor, has recently been approved. However, the efficacy seems to lag behind that in psoriasis, and topical corticosteroid is often used concomitantly, which reflects the complexity in atopic dermatitis pathogenesis. For the other immune based skin disease, adalimumab is approved for hidradenitis suppurativa, omalizumab for chronic idiopathic urticaria and rituximab for pemphigus vulgaris (in United states). Despite the high efficacy and relative safety of these biologics, the high costs of these agents limit the accessibility to most patients, an important issue which hopefully can be resolved after the patents expire. Also, we hope more unsolved skin diseases can be better managed with the approval of novel agents and understanding of their pathogenesis.