ANAPHYLAXIS - A REVIEW OF 266 CASES

Background: A presentation of findings from a large population of anap hylaxis cases. Methods: Retrospective chart review and follow-up quest ionnaire provided data on 266 subjects (113 males and 153 females) age d 12 to 75 years (mean age, 38 years) who were referred to a universit y-affiliated private allergy-immunology practice in Memphis, Tenn, for evaluation and management of:anaphylaxis from January 1978 through Ma rch 1992. Results: Of 266 subjects, 162 (61%) had three or more anaphy lactic episodes, 41 (15%) had two episodes, and 63 (24%) had one episo de. Atopy was present in 98 individuals (37%). Physicians thought food s, spices, and food additives caused anaphylaxis in 89 individuals (34 %); crustaceans and peanut accounted for about half of these cases. Me dications were thought to have caused the anaphylactic episodes in 52 individuals (20%); nonsteroidal anti-inflammatory drugs in about half of these cases. Other probable causes included exercise (n = 19), late x (n = 2), hormonal changes (n = 2), and insect bites (n = 4). A suspe cted cause could not be determined in 98 individuals (37%). These subj ects were diagnosed as having idiopathic anaphylaxis. Of the 266 subje cts, 102 responded to a follow-up survey; 68 (67%) of the 102 were tho ught to have identifiable causes of anaphylaxis (32 of whom [47%] fail ed to carry epinephrine syringes for self-administration despite instr uctions to do so). In contrast, of 34 subjects with idiopathic anaphyl axis who responded to the survey, only three (9%) did not carry epinep hrine. Conclusions: (1) Atopy is common in subjects who experience ana phylaxis, regardless of its origin; (2) crustaceans and nonsteroidal a nti-inflammatory drugs are the most common food and medication groups, respectively, thought to cause anaphylaxis; (3) causative agents can be identified for two thirds of the subjects, and recurrent attacks ar e the rule; and (4) subjects with idiopathic anaphylaxis are more like ly to carry epinephrine for self-administration than those with identi fiable causes.