台中榮民總醫院 過敏免疫風濕科過敏氣喘特別門診 陳怡行醫師 過敏原皮膚試驗與判讀 台中榮民總醫院 過敏免疫風濕科過敏氣喘特別門診 陳怡行醫師

Modified Coombs and Gell Classification of Allergic Reactions ◎ Allergic reactions are unwanted inflammatory reactions to external agents, which is harmless to most people. The reactions are typically classified into four types according to the proposal of Coombs and Gell in 1963. The classification has been recently modified by Kay into 7 subtypes according to the molecule and cells that involved. The type I , or immediate type allergic reactions is mediated by cross-linking of menbrane-bound IgE by allergen, causing allergic rhinitis, anaphylaxis, allergic asthma and most of the early phase of allergic reactions. Kay, A.B. Allergy and Allergic Diseases 2008,3-22.

The IgE-dependent allergic inflammation Initial exposure: sensitization Re-exposure: allergic reaction IL 4 Th2 FceRI IL 5 IL 13 B We know that in atopic individuals, exposure to allergens drive naive T cells to Th2 cells and leading B cells to produce IgEs. Re-exposure of the allergens causing allergen Cross-linking of high affinity IgE receptors sitting on the surface of mast cells and basophils , in sensitive subjects, leads to the typical acute symptoms of allergic reactions, which can vary from mild itching eyes, nose, running nose, hives to severe lift-threatening bronchospasm or even anaphylactic shock. Identifying the offending allergens is essential in understanding allergic diseases. Mast cells/Basophils Ig E

第一型過敏反應 (立即型) 皮膚發癢,潮紅 蕁麻疹/血管性水腫 打噴涕/流清鼻水/鼻塞 眼睛癢/流眼淚/結膜充血水腫 支氣管攣縮,氣喘發作 嘔吐,腹部絞痛,腹瀉 過敏性休克

第二型過敏反應(cytotoxic) Allergen- specific IgG 或IgM作用在細胞上 Onset: 不一定 溶血 白血球低下 血小板低下 Onset: 不一定

第三型過敏反應 免疫複合體在組織沉積,引起補體活化及發炎反應 Onset : Expose過敏原1-3週後 Serum sickness 發燒 皮疹 關節痛 血管炎 淋巴結種大 腎絲球腎炎 Onset : Expose過敏原1-3週後

第四型過敏反應 過敏性接觸性皮膚炎 固定性藥疹 Erythema multiforme Steven-Johnson syndrome Toxic epidermal necrolysis

常見過敏病 過敏性氣喘 過敏性鼻炎/過敏性結膜炎 異位性皮膚炎 過敏性休克 蕁麻疹/血管性水腫 過敏性接觸性皮膚炎 食物過敏 藥物過敏

何時需要建議病患做過敏原檢查? Atopic dermatitis Allergic rhinitis Asthma Urticaria Angioedema Anaphylaxis Insect venom allergy Drug reaction Chronic cough Chronic rhinitis Chronic conjunctivitis Chronic sinusitis Nasal polyp Serous otitis media Chronic otitis media

做什麼檢查? In vitro test In vivo test Prick-puncture test Allergen-specific IgE Phadia ImmunoCAP MAST Basophil histamine releasing test BASOtest Lymphocyte transformation test In vivo test Prick-puncture test Intra-dermal skin test Inhalation challenge Oral challenge test Patch test

以過敏病的免疫機轉來選定適當的過敏檢查 疾病的免疫機轉 Laboratory tests Type I (IgE-mediated) Skin testing, RAST Serum tryptase Type II (IgG-mediated) Direct or indirect Coomb’s test, ANA,anti-platelet Abanti-histone Ab, AMA, AMiA, etc. Type III (immune complex) ESR, CRP, CIC, C3, C4, CH50, biopsy Type IV (delayed , cell mediated) Patch test, lymphocyte transformation test

Allergen Specific IgE Test

過敏原貼布試驗Patch test

過敏原皮膚試驗

Gell and Coomb’s Classification of allergic Reactions Allergic reactions are abnormal reactions of our immune system to harmless substances that causing unwanted inflammation and tissue damages. Gell and Coomb had classified the allergic reactions into four types base on their principle mechanisms.

實作及作業 每人右手做skin prick test 左手做Penicillin skin test (intra-dermal test) Positive control (histamine 1mg/ml) Negative control (phosphate-buffered saline) Allergen : house dust mite (Der p + Der f) 左手做Penicillin skin test (intra-dermal test) Allergen: Penicillin 1:1000 (10000U) 0.05ml Negative control :Water for injection 0.05ml 20分鐘後判讀

=size of positive control ±1mm2 判讀 Grade Size (mm x mm) (-) 1+ > Negative control 3mm but <1/2 positive control 2+ ≥ ½ but< positive control 3+ =size of positive control ±1mm2 4+ >positive control with pseudopods