Scranton Stephen E, Gonzalez Erika G, Waibel Kirk H
Department of Allergy and Immunology, Landstuhl Regional Medical Center, Landstuhl.
J Allergy Clin Immunol. 2009 Feb;123(2):493-8. doi: 10.1016/j.jaci.2008.10.026. Epub 2008 Dec 6.
The reported incidence of biphasic anaphylactic reactions varies from 1% to 20%. Reported risk factors for biphasic reactions include a delay in epinephrine administration and a longer interval to initial improvement. To date, only 4 cases of biphasic reactions after allergen immunotherapy have been reported.
We sought to determine the incidence, clinical characteristics, and risk factors for biphasic reactions after allergen-specific immunotherapy.
Patients who were treated with epinephrine for systemic reactions after allergen immunotherapy were prospectively enrolled. Patients were assessed initially and at 24 hours by using a 31-symptom scoring system.
Sixty systemic reactions occurred in 55 patients; 14 (23%) biphasic reactions were reported. Patients experiencing biphasic reactions were more likely to be female (P = .03) and older (P = .01) and require greater than 1 dose of epinephrine (P = .001). There was no difference between groups (biphasic vs no biphasic reaction) regarding the type of immunotherapy, current asthma, initial symptom scores, or time to symptoms, initial epinephrine, or improvement. No specific symptom predicted biphasic reactions. Biphasic reactions were significantly less severe compared with the initial reaction (P < .001), did not occur in children, and did not require additional epinephrine.
Twenty-three percent of patients requiring epinephrine for systemic reactions caused by allergen immunotherapy experienced biphasic symptoms. Patients treated promptly with epinephrine for systemic reactions should be cautioned regarding biphasic reactions; however, biphasic reactions after allergen immunotherapy were mild and did not require additional epinephrine.
双相过敏反应的报告发病率在1%至20%之间。报告的双相反应危险因素包括肾上腺素给药延迟和初始症状改善间隔时间较长。迄今为止，仅报告了4例变应原免疫治疗后的双相反应病例。
我们试图确定变应原特异性免疫治疗后双相反应的发病率、临床特征和危险因素。
前瞻性纳入因变应原免疫治疗后全身反应而接受肾上腺素治疗的患者。最初和24小时时使用31项症状评分系统对患者进行评估。
55例患者发生了60次全身反应；报告了14例（23%）双相反应。发生双相反应的患者更可能为女性（P = 0.03）且年龄较大（P = 0.01），并且需要超过1剂肾上腺素（P = 0.001）。在免疫治疗类型、当前哮喘、初始症状评分、症状出现时间、初始肾上腺素使用或症状改善方面，两组（双相反应组与无双相反应组）之间没有差异。没有特定症状可预测双相反应。与初始反应相比，双相反应明显较轻（P < 0.001），儿童未发生双相反应，且不需要额外的肾上腺素。
因变应原免疫治疗引起的全身反应而需要使用肾上腺素的患者中，23%出现了双相症状。对于因全身反应而迅速接受肾上腺素治疗的患者，应告知其双相反应的情况；然而，变应原免疫治疗后的双相反应较轻，不需要额外的肾上腺素。
