Incidence and characteristics of biphasic and protracted anaphylaxis: evaluation of 114 inpatients

Abstract

Aim: Anaphylaxis is a systemic allergic reaction that potentially causes death. Most anaphylactic reactions are uniphasic, but some cases may be biphasic or protracted. However, these clinical epidemiology concepts are unfamiliar in Japan. Therefore, we have investigated the incidences and characteristics of patients with biphasic and protracted anaphylaxis. Methods:We retrospectively evaluated patients with anaphylaxis in a single emergency medical center located in Yokohama, Japan from April 2009 to March 2012. We analyzed the incidences and characteristics of patients with biphasic and protracted anaphylaxis who needed to be admitted.Results: A total of 253 patients were diagnosed with anaphylaxis and 114 patients needed to be admitted. Of the 114 patients, 103(90.4%) were uniphasic, 7 (6.1%) were biphasic and 4 (3.5%) were protracted anaphylaxis. The most common antigens were foods and drugs. The median onset of a biphasic reaction was 8 h and dermatologic symptoms were mostly observed. Regarding severity, mild symptoms were seen in four cases, similar symptoms to the initial reaction were seen in two cases, and only one case was severe. The duration of protracted anaphylaxis varied from 2 to 8 days. Conclusion:The incidence of biphasic and protracted anaphylaxis in inpatients was 6.1% and 3.5%, respectively. The median onset of biphasic reaction was 8 h, and most symptoms were mild or similar to the initial reaction. We suggest that patients with anaphylaxis need an 8-h and ideally a 24-h observation period in order to monitor possible biphasic reactions. The duration of protracted anaphylaxis was up to 8 days.

Anaphylaxis—a 2020 practice parameter update, systematic review, and Grading of Recommendations, Assessment, Development and Evaluation (GRADE) analysis

“…199 Topic area 2 included studies. The following studies were used in the analyses of questions 2 to 5: Question 2: Alqurashi et al, 42 Brady et al, 173 Brown et al, 21 Calvani et al, 175 Douglas et al, 178 Ellis and Day, 39 Grunau et al, 200 Guiot et al, 201 Inoue and Yamamoto, 179 Jirapongsanunuruk et al, 180 Kawano et al, 202 Ko et al, 181 Lee et al, 203 Lee and Greenes, 142 Lee et al, 182 Lertnawapan and Maek-a-nantawat, 183 Lin et al, 204 Manuyakorn et al, 185 Mehr et al, 186 Michelson et al, 166 Oya et al, 205 Poachanukoon and Paopairochanakorn, 189 Rohacek et al, 41 Scranton et al, 190 Smit et al, 191 Sricharoen et al, 55 Stark and Sullivan, 37 Vezir et al 192 Question 3: Chang et al, 206 Francis et al, 207 Jerzak et al, 208 Mach et al, 209 Onetto et al, 210 Rougier, 211 Seki et al, 212 Shen et al, 213 Thompson et al, 214 Trudeau et al, 215 Weiss et al 198 Question 4: Abe et al, 216 Katayama et al, 217 Kolbe et al,…”

Low Incidence of Biphasic Allergic Reactions in Patients Admitted to Intensive Care after Anaphylaxis

“…The underlying mechanism behind biphasic allergic reaction is unknown, but it is suggested to include various types of immune responses, large doses of antigen (e.g., IV antibiotics), continuous exposure to the allergen (e.g., food in stomach), inadequate treatment of the initial reaction, lack of postreaction treatment, or simply just a recurrence of a temporarily interrupted protracted initial reaction. 8,9 At present, there is no consensus in international guidelines on how long a patient should be observed after anaphylaxis, and the recommended observation period varies in the range of 4 to 24 h, based on the perceived risk of biphasic reactions. 2,10 Working on the assumption that patients with the most severe symptoms may be at highest risk of protracted or biphasic reactions, this study investigated patients admitted to intensive care units for observation after anaphylaxis.…”

Food allergy in children

“…Compared to venom/drug induced anaphylaxis gastrointestinal symptoms are common in food induced anaphylaxis (41%) 19 . Generally, symptoms could be uniphasic (symptoms do not recur during the same episode), biphasic (recurrence of symptoms about 8 hours after previous reaction) or protracted (symptoms last for hours or days) 19,22 . Diagnosis is primarily clinical.…”