你六月停C之後第一次用番?
你之前用Dr Sam嘅brightly精華係AA2G ascorbyl glucoside,neutrogena膠囊係L-AA 左旋維他命C
如果你今次一用番C就起粒粒有可能係(A)20%本身高濃度高刺激性,(B)外用形式維他命C敏感
如果你用過三隻或以上唔同維他命C型態嘅護膚品都會起粒粒的話,就高機率VC不耐受
早C晚A係行銷,每賣出一支A醇就可以賣多支維C,雙倍收入
倖存者偏差
好多時候ACD皮炎都係發生喺護膚品愛用者身上,搽得越多累計過敏風險越高
維他命C呢個時代嘅熱潮令好多護膚品愛用者都人手一支
加加埋埋報告上會產生選擇性偏差,形成維他命C特別易敏感嘅現象
如果有新熱潮「二十歲後每日都要用維他命D精華抗老!」,咁就會多咗人回報維他命D敏感
其實都唔係個個用到A,只不過A反應臭名昭著,用唔到都會覺得好理所當然
當鋪天蓋地宣傳維他命C百利無一害,就會加倍放大維他命C嘅不良反應
壞人做一件好事,同埋好人做一件壞事
另一方面完全維他命C敏感嘅例子都好個別,ACD個案中有部分係因為濃度太高太刺激
護膚品中維他命C精華尤其容易中招,因為VC本質上難保存活性難滲透肌膚,廠商為咗確保療效就有幾濃加幾濃
歐美品牌流行落安全劑量嘅上限(甚至過埋),日本品牌流行開起效劑量嘅下限
其實睇番好多護膚品最後幾個材料都會通常係微量VC或者VE,用嚟防腐保鮮,大部分人都唔會有反應
如果真係過敏,落幾少都會過敏
一個花生過敏嘅人食半粒花生同花生醬三文治都係會過敏,差別在於後者可能要直入醫院
最後想再強調一個原則,由Post 1 #1開始,都係「甲之砂糖乙之砒霜」,唔存在所有人都通用有效嘅印度神油
除咗護膚品,保健品、疫苗、藥劑、化療、免疫療乜乜乜全部都係
趨勢將會走向個人化,願科技早日突飛猛進
according to current literature, almost all vitamins contained in topical products are able to induce allergic reactions, with the exception of vitamin B2 and vitamin B9.
After the introduction of ascorbic acid semisynthetic esters in cosmetics, 62 ACD of the face and neck was reported in middle‐aged female patients. Also 3‐O‐ethylascorbic acid proved to be an emerging contact allergen due to its increasing diffusion as a whitening and antioxidant agent in cosmetics. 63 , 64 Since the first case of ACD to ascorbic acid described in 1980, 29 several cases of ACD to vitamin C, demonstrated through patch testing at different concentrations and vehicles, have been described. 65 , 66 , 67
Foti, C., Calogiuri, G., Nettis, E., De Marco, A., Stingeni, L., Hansel, K., Di Bona, D., Carlucci, P., Romita, P., & Barbaud, A. (2022). Allergic contact dermatitis from vitamins: A systematic review.
Health Science Reports, 5(6).
https://doi.org/10.1002/hsr2.766