title: Multiphasic anaphylaxis: an uncommon event in the emergency department.
abstract: OBJECTIVE
  To determine the rate of clinically significant recurrence of symptoms in patients treated for anaphylaxis in the ED.
  
  
  METHODS
  Retrospective chart review of out-of-hospital, ED, and hospital records over 4.5-year period (July 1991 to December 1995) at a university hospital ED with an annual patient volume of 60,000. Subjects were ED anaphylaxis patients with > or = 2 of the following 3 organ systems involved: cutaneous, respiratory, and cardiovascular. The major outcome criterion was recurrence of symptoms after ED release. Recurrences were sought at the primary treatment hospital and at surrounding hospitals (radius of 75 miles from the primary institution) within a 7-day period from the initial visit. Review of the state death registry also was made to verify the absence of out-of-hospital deaths.
  
  
  RESULTS
  The medical records of 1,261 allergic reaction patients were reviewed, with 67 (5.3%) cases of anaphylaxis identified. Symptoms and signs in patients during the ED phase included: dyspnea, 42 (63%); pruritus, 38 (57%); emesis, 27 (41%); throat/chest tightness, 25 (37%); orthostatic complaints, 12 (18%); urticaria, 47 (70%); circulatory shock, 32 (48%); upper airway angioedema, 7 (33%); stridor, 11 (16%); and bronchospasm, 20 (30%). Of the 67 patients, 93% had immediate resolution and remained asymptomatic for a mean time of 4.2 hours in the ED. Protracted reaction occurred in 5 cases (3 using beta-adrenergic blocking agents). For 19 (28%) patients admitted to hospital, the mean hospital length of stay was 63 hours. Only 2 (3%) recurrent cases were identified, both manifested solely by urticaria.
  
  
  CONCLUSIONS
  Recurrent anaphylactic reactions were rare, occurring in 3% of cases and without life threat in this patient population. Selective outpatient management of patients with severe anaphylactic reactions that promptly respond to therapy with complete, rapid resolution may be reasonable. Further study of this medical emergency is required to develop criteria to guide the choice of an outpatient disposition.
authors.affiliation: Department of Emergency Medicine, University of Virginia School of Medicine, Charlottesville, USA. wb4z@galen.med.virginia.edu
authors.forename: W J
authors.initials: WJ
authors.lastname: Brady
authors.forename: S
authors.initials: S
authors.lastname: Luber
authors.forename: C T
authors.initials: CT
authors.lastname: Carter
authors.forename: A
authors.initials: A
authors.lastname: Guertler
authors.forename: G
authors.initials: G
authors.lastname: Lindbeck
mesh_terms: D000328:Adult; D000707:Anaphylaxis / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology*; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data; D005260:Female; D006634:Histamine H1 Antagonists / Q000627:therapeutic use; D006785:Hospitals, University; D006801:Humans; D008297:Male; D008499:Medical Records; D012008:Recurrence; D012189:Retrospective Studies; D014768:Virginia / Q000453:epidemiology
chemical_list: D006634:Histamine H1 Antagonists