牛皮癬
牛皮癬是常見的皮膚病，導致皮膚出現紅腫發炎斑塊。牛皮癬的嚴重程度因人而異，而且或會不時發作及消失。這種疾病不會傳染。
以下內容由保柏健康資訊顧問團隊提供，一切資料均根據可靠而有醫學證明的資料而編寫，並經保柏的醫學顧問核實。內容僅供參考，不能取代合資格的醫護人員給予閣下之個人建議。
皮膚由多個皮層組成，最表層的老化細胞不斷脫落，由下層的新細胞更替。這個更新周期一般需時28日。牛皮癬患者的皮膚患處更新周期加快，最短可能縮至2至6天，新皮膚細胞尚未發育完全便移至表面，在皮膚形成厚塊(斑塊)，此外皮下並會積聚一種名為T細胞的血細胞，引致發炎。
每100人當中約兩人患有牛皮癬，初次發病的年齡因人而異，但一般病例均為15至30歲的年青成人或50至60歲的中年人，男女患者數目相若。
牛皮癬會終生影響患者，很難完全根治，但病情往往有時候嚴重但有時候較緩和，原因不明。換言之，嚴重時患者可能會突然觸發徵狀，平時則難以察覺。
牛皮癬並非傳染疾病，不會從別人身上感染到，患者也不會把疾病傳給他人。
牛皮癬分為多種類型。
斑塊狀牛皮癬(Plaque Psoriasis)
斑塊狀牛皮癬是最常見的一類牛皮癬，患者皮膚出現粉紅或紅色鱗狀斑塊(突塊)，膝及手肘最明顯。
屈側型牛皮癬(Flexural Psoriasis)
屈側型牛皮癬又稱逆向型牛皮癬，患處位於皮膚摺疊處，例如腋下及腹股溝，這些位置的皮膚較薄和敏感。屈側型牛皮癬會導致皮膚呈現鮮紅色的閃亮斑塊，或會輕微痕癢或不適。屈側型牛皮癬患者的身體其他部位可能同時出現斑塊。
膿皰型牛皮癬(Pustular Psoriasis)
膿皰型牛皮癬是罕見的嚴重牛皮癬，患者出現含膿的皮皰(膿皰)，假如佈滿全身便稱為泛發性膿皰型牛皮癬(Generalised Pustular Psoriasis)，嚴重者足以致命，患者一般須要住院。
紅皮型牛皮癬(Erythrodermic Psoriasis)
紅皮型牛皮癬是另一種罕見的嚴重牛皮癬，患者全身皮膚紅腫發炎，似被太陽曬傷。皮膚發炎或會引致多種嚴重併發症，患者一般須要入院治療。紅皮型牛皮癬通常只見於本身已患有另一種牛皮癬的患者。
滴狀牛皮癬(Guttate psoriasis)
滴狀牛皮癬會導致細小的鱗狀炎皰，突然佈滿全身，外貌像雨點。這種牛皮癬通常只見於兒童及年青成人，一般是喉部感染後觸發。
牛皮癬的徵狀
牛皮癬形態繁多，但患者的皮膚一般會厚化和出現銀/白鱗狀的紅色斑塊。斑塊的大小不盡相同，與周圍皮膚外貌明顯不同。此外皮膚並會感到痕癢或疼痛。徵狀輕微的患者或會不察覺患上牛皮癬。
某些類型的牛皮癬或會影響頭皮，令頭皮發紅及脫皮，此外亦可能影響指甲，導致出現坑紋、厚化或甲床剝離。
如有任何上述徵狀，應諮詢醫生。
醫生會詢問患者徵狀並進行檢查，一般也可從徵狀和觀察皮膚及指甲診斷牛皮癬。如不能確診或牛皮癬屬下列情況，醫生可能轉介患者到皮膚專科醫生：
- 範圍廣泛或情況嚴重
- 影響學業或工作
- 治療無效
醫學界對牛皮癬的具體成因尚未能確定，但相信遺傳基因是最大因素，因為家族成員有這種疾病的人士患牛皮癬風險較高。儘管如此，這類人士也不一定會患牛皮癬。
環境因素亦常會觸發牛皮癬，包括咽喉細菌感染、某些藥物或壓力等，但許多患者沒有特別的觸發因素。
遺傳基因和環境觸發因素會影響皮膚的免疫細胞造成發炎，使皮膚開始以異常快的速度製造新細胞，形成牛皮癬斑塊。究竟是甚麼緣故導致免疫系統如此，目前尚未清楚。
牛皮癬雖然沒法根治，但卻有多種療法可以舒緩徵狀。這些治療的成效因人而異，有些患者可能須要嘗試多種方法才找到最適合的方案。
自我護療
醫生或會建議患者使用潤膚膏 — 即潤膚霜或潤膚液，這類產品可軟化及舒爽皮膚。此外沖溫水浴亦可軟化牛皮癬，醫生或會建議洗澡時添加浴油。
藥物
局部治療
患者可選用外塗的治療藥物。醫生可處方藥霜或軟膏，具體類型及藥效強度視乎牛皮癬種類而定。以下是常用的外用治療藥物：
- 焦油劑可消炎及減少皮屑，常用於治療頭皮上的牛皮癬，但這類藥物或有難聞氣味，也容易弄髒衣物。
- 含地蒽酚(Dithranol)的藥霜功效極佳，但容易弄髒衣物及刺激健康皮膚，所以醫生一般不會處方。
- 類固醇劑常用於治療局部牛皮癬(例如手肘或膝蓋)。手掌及腳掌或頭皮患處或可使用強效配方。類固醇藥霜一般只宜短期塗用。
- 維他命D衍生素(例如卡泊三醇(Calcipotriol)或他卡西醇(Tacalcitol))使用上比其他產品方便，但可能刺激皮膚。
- 維他命A衍生素(視黃醇(Retinoids))亦可能有效，但容易導致皮膚刺激反應。
口服藥物
如局部治療沒法控制徵狀，或牛皮癬範圍廣泛，醫生或會處方口服藥片，例如：
- 甲氨蝶呤(Methotrexate)
- 阿維A(Acitretin)
- 環孢素(Ciclosporin)
- 羥基脲(Hydroxycarbamide)
醫生會提醒女性患者服用這類藥物期間不要懷孕，有些情況下服藥後一段時間也不宜生育。部分藥片亦會影響男性，醫生會提醒患者服藥期間不要令配偶成孕，否則可能對胎兒造成嚴重損害。
生物藥物是較新興的牛皮癬治療方案，而且成效可能極佳，但卻一般限於嚴重牛皮癬患者，又或曾嘗試其他療法無效的患者。生物藥物是液劑，可用針筒注射或在臂部靜脈輸液。這類藥物包括：
- 依那西普(Etanercept)
- 阿達木單抗(Adalimumab)
- 英夫利西單抗(Infliximab)
- 優特克單抗(Ustekinumab)
服藥前必須諮詢醫生意見，並詳閱藥物隨附的病人須知說明。
上述各種藥物是否可以使用或醫生會否使用因國家而異。
光效治療
醫生會視乎患者的牛皮癬類型及影響範圍，建議接受紫外光治療。
光效治療機像花灑浴間，內設多支光管。
- UVB紫外線光效治療：用人工UVB紫外線照射皮膚。UVB紫外線存在於天然陽光，患者一般每星期治療兩至三次，為期最長8星期。
- UVB紫外線光效治療亦可配合其他局部治療同時進行，例如使用焦油劑。這種混合局部治療的方法或可增強皮膚對UVB紫外光的敏感度，有助控制徵狀。
- 補骨脂素(Psoralen)配合UVA紫外線光效治療：結合一種使皮膚對陽光更敏感的藥物(補骨脂素)與定量UVA紫外線治療。補骨脂素可採用藥片或直接塗於皮膚。治療通常每星期兩次，最長為期10星期。
來源
- Psoriasis – an overview. The British Association of Dermatologists. www.bad.org.uk, published May 2012
- Psoriasis. eMedicine. www.emedicine.medscape.com, published June 2012
- Psoriasis: signs and symptoms. American Academy of Dermatology. www.aad.org, accessed 13 June 2012
- Guttate psoriasis. eMedicine. www.emedicine.medscape.com, published May 2012
- Psoriasis. DermNet NZ. www.dermnetnz.org, published May 2012
- About psoriasis. The Psoriasis Association. www.psoriasis-association.org.uk, accessed 13 June 2012
- Psoriasis. Prodigy. www.prodigy.clarity.co.uk, published May 2010
- Etanercept and efalizumab for the treatment of adults with psoriasis. National Institute for Health and Clinical Excellence (NICE), 2006. www.nice.org.uk
- Infliximab for the treatment of adults with psoriasis. National Institute for Health and Clinical Excellence (NICE), 2008. www.nice.org.uk
- Ustekinumab for the treatment of adults with moderate to severe psoriasis. National Institute for Health and Clinical Excellence (NICE), 2010. www.nice.org.uk
- Ultraviolet light therapy. The Psoriasis Association. www.psoriasis-association.org.uk, accessed 14 June 2012
- Personal communication, Dr M Ardern-Jones, Consultant Dermatologist/Senior Lecturer, Sir Henry Wellcome Laboratories, Southampton General Hospital, June 2012
- Psoriasis – a simple explanation. The Psoriasis and Psoriatic Arthritis Alliance. www.papaa.org, accessed 14 June 2012
- Frequently asked questions. The Psoriasis and Psoriatic Arthritis Alliance. www.papaa.org, accessed 14 June 2012
- Frequently asked questions: psoriasis in spring, summer, fall and winter. The National Psoriasis Foundation. www.psoriasis.org, accessed 14 June 2012
- Ebetrex 10mg/ml solution for injection, pre-filled syringe. electronic Medicines Compendium. www.medicines.org.uk, published March 2012
- Hydrea 500mg hard capsules. electronic Medicines Compendium. www.medicines.org.uk, published June 2012
- Neoral soft gelatine capsules, Neoral oral solution. electronic Medicines Compendium. www.medicines.org.uk, published February 2012
- Neotigason 10mg capsules. electronic Medicines Compendium. www.medicines.org.uk, published July 2011
- Condoms (male and female): your guide. The Family Planning Association. www.fpa.org.uk, published March 2011
- Sunbeds. The British Association of Dermatologists. www.bad.org.uk, accessed 15 June 2012
- Exposure to artificial UV radiation and skin cancer. International Agency for Research on Cancer, 2006, Working Group Report 1. www.iarc.fr
- What is skin camouflage? Skin Camouflage Network. www.skincamouflagenetwork.org.uk, accessed 18 June 2012
- Find out about the skin camouflage team. Changing Faces. www.changingfaces.org.uk, accessed 18 June 2012
來源
- Psoriasis – an overview. The British Association of Dermatologists. www.bad.org.uk, published May 2012
- Psoriasis. eMedicine. www.emedicine.medscape.com, published June 2012
- Psoriasis: signs and symptoms. American Academy of Dermatology. www.aad.org, accessed 13 June 2012
- Guttate psoriasis. eMedicine. www.emedicine.medscape.com, published May 2012
- Psoriasis. DermNet NZ. www.dermnetnz.org, published May 2012
- About psoriasis. The Psoriasis Association. www.psoriasis-association.org.uk, accessed 13 June 2012
- Psoriasis. Prodigy. www.prodigy.clarity.co.uk, published May 2010
- Etanercept and efalizumab for the treatment of adults with psoriasis. National Institute for Health and Clinical Excellence (NICE), 2006. www.nice.org.uk
- Infliximab for the treatment of adults with psoriasis. National Institute for Health and Clinical Excellence (NICE), 2008. www.nice.org.uk
- Ustekinumab for the treatment of adults with moderate to severe psoriasis. National Institute for Health and Clinical Excellence (NICE), 2010. www.nice.org.uk
- Ultraviolet light therapy. The Psoriasis Association. www.psoriasis-association.org.uk, accessed 14 June 2012
- Personal communication, Dr M Ardern-Jones, Consultant Dermatologist/Senior Lecturer, Sir Henry Wellcome Laboratories, Southampton General Hospital, June 2012
- Psoriasis – a simple explanation. The Psoriasis and Psoriatic Arthritis Alliance. www.papaa.org, accessed 14 June 2012
- Frequently asked questions. The Psoriasis and Psoriatic Arthritis Alliance. www.papaa.org, accessed 14 June 2012
- Frequently asked questions: psoriasis in spring, summer, fall and winter. The National Psoriasis Foundation. www.psoriasis.org, accessed 14 June 2012
- Ebetrex 10mg/ml solution for injection, pre-filled syringe. electronic Medicines Compendium. www.medicines.org.uk, published March 2012
- Hydrea 500mg hard capsules. electronic Medicines Compendium. www.medicines.org.uk, published June 2012
- Neoral soft gelatine capsules, Neoral oral solution. electronic Medicines Compendium. www.medicines.org.uk, published February 2012
- Neotigason 10mg capsules. electronic Medicines Compendium. www.medicines.org.uk, published July 2011
- Condoms (male and female): your guide. The Family Planning Association. www.fpa.org.uk, published March 2011
- Sunbeds. The British Association of Dermatologists. www.bad.org.uk, accessed 15 June 2012
- Exposure to artificial UV radiation and skin cancer. International Agency for Research on Cancer, 2006, Working Group Report 1. www.iarc.fr
- What is skin camouflage? Skin Camouflage Network. www.skincamouflagenetwork.org.uk, accessed 18 June 2012
- Find out about the skin camouflage team. Changing Faces. www.changingfaces.org.uk, accessed 18 June 2012