The incidence, aetiology and management of anaphylaxis presenting to an accident and emergency department

Abstract

We retrospectively studied anaphylaxis in an A&E department from computerized records. In 1993 (Study A), of 55,000 patients seen in casualty, nine had severe anaphylaxis (ANA) with loss of consciousness (LOC) or fainting (about 1: 6000). Fifteen had generalized allergic reactions (GR) without LOC or fainting, but including dyspnoea due to laryngeal oedema or asthma, angioedema and/or urticaria. Thus there were 24 (about 1:2300) generalized reactions involving hypotension and/or respiratory difficulty. A further case diagnosed as hyperventilation syndrome was probably a wasp sting GR. Six cases of urticaria and/or angioedema were also identified. Of the nine with ANA, a possible cause was identified in eight (3 stings; 2 drugs; 3 foods). There was delay in arrival in A&E: hypotension was noted in three and had resolved spontaneously in six. Only 3/9 were related with adrenaline: i.v. hydrocortisone and chlorpheniramine was the mainstay of treatment. No investigation was recommended nor advice given on future management. Four patients were later referred to our allergy clinic by their GPs. In study B (aug-Oct 1994), nine cases of ANA were identified (1:1500), eight due to bee or wasp stings. The increased incidence was probably related to more detailed history-taking. Only three were treated with adrenaline. The use of adrenaline for future anaphylaxis was discussed with six patients, and five were referred to our allergy clinic. A reaction to the same allergen had occurred previously in 24%. Improved awareness of anaphylaxis and its management is necessary.