Dr. Simons discussed anaphylaxis.Children rarely manifest hypotension in anaphylaxis until premorbid state. Don't wait for this to occur before treating! A study of infant food-induced anaphylaxis showed that 51% were fed the food by a non-parent caregiver.
Minutes matter, especially with HAE as its onset can be quite sudden and fatal (2 mins in some cases).
A recent study suggests that any antihypertensive medication on board increases severity of anaphylaxis - not just beta-blockers.
Systemic mastocytosis is a risk factor for anaphylaxis to stinging insects and possibly also medications. Rudders study in the Annals showed only 16% of patients who had venom anaphylaxis eventually got to an allergy appointment.
PAF and tryptase
PAF levels correlate better with anaphylaxis severity than tryptase or histamine. Elevated PAF levels in anaphylaxis correlate with severity. In a prospective study of adults, patients only had elevated tryptase in 63% of cases but there was a positive correlation with severity.
Baseline tryptase levels in very young children are much higher making the diagnosis of anaphylaxis more difficult. Atopic (but otherwise healthy) infants less than 3 months of age had mean tryptase levels of 14 mcg/mL (normally to be considered high).
Treatment
WAO anaphylaxis guidelines emphasized chest compressions above airway and breathing (CAB rather than ABCs). A Montreal study at MCH showed a 73% likelihood of getting epinephrine in the Emergency Dept with anaphylaxis. A "World Record".
A study by Park et al. (JACI 2011 128:1127-8) documented that cetirizine PO had same onset of urticaria relief as IM diphenhydramine, without sedation.
A Cochrane review of colloid vs crystalloids for volume resuscitation in anaphylaxis showed that colloid was no better, so it is not recommended.
Pregnant women having anaphylaxis should lie on their left side to avoid inferior vena cava compression.
Epinephrine
Comorbidities are higher in the elderly with risk of MI and arrhythmia more so than in younger patients. In the elderly there were increased CV symptoms, increased likelihood of admission to hosp and less likelihood to have Epi prescription.
Acute coronary syndrome can occur in anaphylaxis before or after epinephrine administration. There is no absolute contraindication to the administration of epinephrine in anaphylaxis. Dr. Simons related a case report where a dental patient died of anaphylaxis and dental team didn't give Epi because his health "forbade it".
A UK study of teens showed Epi use in only 16.7% of cases of anaphylaxis despite severe disease.
The correct epinephrine auto injector use is an acquired skill. Always worth a refresher.
Twitter summary made possible by @IgECPD @allergydoc4kidz @DrAnneEllis
Three allergists did a great job posting updates from the 2013 meeting of the Canadian Society of Allergy and Clinical Immunology (#CSACI): @IgECPD @allergydoc4kidz @DrAnneEllis. Compared to year 2011, this represents 300% growth in Twitter use by the Canadian allergists (from one to three participants, stable since 2012.
For comparison, here are the tweets from the previous #CSACI meetings: http://allergynotes.blogspot.com/search/label/CSACI
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