Table 3 Diagnosis, initial treatment, and self-treatment in community settings

Diagnosis [ 78 – 90 ]

In a prospective controlled study of ED patients with anaphylaxis, up-regulation of innate inflammatory gene networks was reported. On ED arrival, two genes were expressed; one hour after arrival, 67 genes were expressed; and three hours after arrival, 2801 genes were expressed. Genomic responses provide new insights into the potential release of a cascade of mediators in anaphylaxis [90].

Initial treatment [ 91 – 103 ]

Early injection of epinephrine in anaphylaxis, defined as initial injection before ED arrival, significantly reduced the likelihood of hospital admission, compared with initial epinephrine injection after ED arrival [92].

Epinephrine was injected before cardiac arrest in only 23 % of 92 individuals who experienced a fatal anaphylaxis episode [93].

In an observational study, data confirmed the safety of IM epinephrine injection, typically given through an epinephrine auto-injector: (adverse events 1 %, and no overdoses). In contrast, IV bolus injections were associated with significantly more adverse events (10 %) and overdoses (13 %) [99].

In a systematic review and meta-analysis of 27 studies, 4.7% of 4114 patients with anaphylaxis had biphasic episodes (range 0.4% to 23.3%). Patients who presented with hypotension or who had an unknown inciting trigger were at increased risk. The data suggested that for patients with anaphylaxis who are treated successfully in an ED, the duration of observation should be risk-stratified according to the clinical characteristics and severity of the episode [101].

Long-term management: self-treatment in community settings [ 104 – 118 ]

Patients who were treated in an ED for anaphylaxis benefited from referral to A/I specialists who clarified the diagnosis and correctly identified and confirmed specific anaphylaxis triggers [104].

Novel EAIs are now available in some countries. The compact Auvi-Q can be used correctly on first attempt by 93 % of parents who have never seen or heard it before. The Emerade is available in 0.15 mg, 0.3 mg, and 0.5 mg doses. The 0.3 mg and the 0.5 mg dose EAIs have a 25 mm long needle. EAIs differ significantly with regard to size, ease of carrying, ease of use, needle protection, and robustness. They are not interchangeable [107, 108].