簡介
類風濕關節炎是一種自身免疫系統異常的慢性炎性關節疾病。疾病可引致關節出現痛楚、腫脹、變形和僵硬。患者的活動能力有機會大受影響，對他們的整體健康以至生活質素，帶來不能逆轉的傷害。該病在香港的患病率為0.35%，比其他已發展城市低（0.5-1.0%）(1)。 統計發現，30至50歲屬於類風濕性關節炎的患病高峰期，而女性比男性患上此病機會高約三倍。
發病機制
醫學界並未完成確定該病的具體成因，但相信和以下因素有一定影響：基因，環境和賀爾蒙因素等等(1)。類風濕關節炎的發病機制未明，臨床病徵亦可能在發病良久後出現。在患有類風濕關節炎的情況下，身體的免疫系統會錯誤地攻擊自身健康的組織。
臨床病徵
雖然任何滑液關節均可受類風濕關節炎影響，但手、手腕和腳則更為普遍受影響(2)。受類風濕關節炎影響的足部，普遍徵狀為關節疼痛、腫脹、腳趾或前掌變形、出現足部厚繭，甚至足部潰瘍和傷口感染。類風濕關節炎的病徵亦可隨著病情而持續反覆，病情得以控制時，亦稱緩解期，病徵會減退。相反，若病情轉差，病徵亦可以加劇。
藥物治療及其對足部的影響
類風濕關節炎的藥物治療上，改善病情抗風濕藥（DMARDs）是常用的口服藥物(3)。甲氨蝶呤是一種類似葉酸的抗代謝物質，可抑制二氫葉酸還原酶以抑制 DNA 的合成，從而抑制細胞生長。甲氨蝶呤針對下肢的常見副作用包括下肢水腫，延長足部傷口癒合進度，以及增加感染風險等等。
足病診療師的角色
足病診療師對於類風濕關節炎的治療主要是減低患者足部痛楚，以及保護足部皮膚、診治足部潰瘍和提供鞋墊治療，從而減低足部受類風濕關節炎的影響。足病診療師可根據個別患者需要而設計及提供特別鞋墊，從而減低腳底的壓力和磨擦 (3)。如類風濕關節炎患者出現因足部關節變型的厚繭硬皮，甚至足部足部潰瘍情況，足病診療師可替患者進行傷口檢查，以及提供適切的護理建議：使用外用敷料，藥膏，甚或進行輔作療法，務求減低傷口感染機會和促進傷口復元。
小結
類風濕關節炎屬於自身免疫系統異常而出現的慢性炎性關節疾病。雖然面對慢性疾病的痛楚和影響並不容易，但配合跨專業治療（MDT），類風濕關節炎患者的生活素質亦可大大提升。如有需要，可向醫生，足病診療師等求助，尋求專業意見。
(此資訊由 Lam Tsz Ho 會員撰寫)
Overview
Rheumatoid arthritis, a.k.a RA, is a chronic autoimmune and inflammatory condition that causes pain, swelling, deformities and stiffness in joints. The functional ability of RA patients could be affected significantly, thus it might lead to irreversible damages. In Hong Kong, it affects around 0.35% of the population, which is lower than that of other developed cities i.e. 0.5-1.0% (1). Statistics show that RA generally starts at the age of 30-50. Women are 3 times more likely to be diagnosed with RA than men.
Pathogenesis
The pathogenesis of RA consists of multiple genetic, environmental and immunologic factors (1). The etiology is uncertain and the trigger adaptive responses and interactions can undergo long before the onset of clinical symptoms. For RA patients, their immune systems mistakenly attack their own healthy cells.
Clinical Presentations
Although any synovial joints in the body can be affected by RA, it usually affects the patient’s hands, feet and their wrists (2). Joint pain, joint swelling, toe deformities, plantar hyperkeratosis formation or even ulcerations and infections are some of the common presentations of RA feet. With RA, there are times when the symptoms get more serious, known as flares, and also times when the symptoms get milder, which is called remission.
RA-related medications and its manifestation to RA feet
RA patients are usually offered a combination of DMARDs (Disease modifying anti-rheumatic drugs) as a first-line treatment. Methotrexate is one of the common medications prescribed and it works by blocking the effects of chemicals released when the patients’ immune cells attack their own joints. However, this medication may potentially cause some side effects such as lower limb swelling and prolonged healing for foot and ankle ulcerations as it might increase vulnerability to damages and infections.
Role of podiatrists
The podiatrist role is here to provide timely clinical management for RA patients with various foot and ankle disorders. Clinical management includes identifying and treating the foot-related pain, skin care, ulceration care and providing insoles therapy if applicable (3). There are various types of insoles and orthotics that can be fitted into the shoes to relieve pressure and reduce friction for the feet. For RA patients who are suffering from joint deformities and foot ulcerations, the podiatrists are here to closely assess the wounds and provide suitable management.
Conclusion
It can be hard to deal with a chronic disease like rheumatoid arthritis. However, multidisciplinary team care could give the best care to RA patients. With podiatry care, the quality of life of them could be much improved. Please speak to your healthcare team if you are struggling to deal with your condition.
(This article is written by member Lam Tsz Ho)
References
1. Gov.hk. [cited 2023 Jan 13]. Available from: https://www.drugoffice.gov.hk/eps/do/en/consumer/news_informations/dm_30.html#a
2. Rheumatoid arthritis (RA) [Internet]. Cdc.gov. 2020 [cited 2023 Jan 13]. Available from: https://www.cdc.gov/arthritis/basics/rheumatoid-arthritis.html
3. Rheumatoid arthritis - treatment. Rheumatology (Oxford) [Internet]. 1997 [cited 2023 Feb 20];36(suppl_1):174–93. Available from: https://www.nhs.uk/conditions/rheumatoid-arthritis/treatment/
4. Podiatrist [Internet]. NRAS. National Rheumatoid Arthritis Society (NRAS); 2020 [cited 2023 Jan 13]. Available from: https://nras.org.uk/resource/the-role-of-the-podiatrist-in-the-management-of-rheumatoid-arthritis/