What is Anaphylaxis?
We’ve all heard of someone “having a reaction” or “being allergic” to something. Usually it’s an everyday thing like:
- Food, such as peanuts, shellfish, or dairy products
- Toxins, such as bee stings or snake venom
- A substance, such as latex or pet dander
Most people’s reactions, called allergies, are mild and take the form of itching, hives, sneezing, or swelling. These symptoms are annoying and inconvenient, but usually once a trigger is known, avoiding it is enough to keep symptoms at bay.
In rare cases, however, reactions can be severe—so severe that a person exposed to a trigger may die if not treated promptly.
These severe reactions are called anaphylaxis. Anaphylaxis can show up right away, or it may appear within hours of exposure to the trigger. Immediate treatment is always required.
Anaphylactic reactions also occur in clinical settings.
One study examined rates of anaphylaxis in an allergy clinic and found that 90.7% of the clinic’s cases of anaphylaxis were attributable to medication administration.1
Another study found that most anaphylaxis-related deaths in the United States (58.8%) between 1999 and 2010 were caused by medications.2
It’s unlikely that you—or your patient—will know if he or she will react to the medication you’re administering. Therefore, you always need to be prepared to treat an anaphylactic reaction.
How to Diagnose Anaphylaxis
The World Allergy Organization has developed Guidelines for the Assessment and Management of Anaphylaxis to help clinicians recognize and treat this potentially life-threatening condition.3
In general, an anaphylactic reaction will involve multiple systems in the body:
Body System Affected | Anaphylactic Symptoms |
Skin | Severe itching, hives, swelling |
Digestive | Swollen lips and/or tongue, nausea, cramps, vomiting |
Respiratory | Constricted airway, difficulty breathing, cough, fluid in lungs |
Circulatory | Lowered blood pressure |
Nervous | Feeling of impending doom, mental confusion |
In other words, the patient is at risk for shock. According to the Mayo Clinic, “When a person is in shock, his or her organs aren’t getting enough blood or oxygen. If untreated, this can lead to permanent organ damage or even death.”4
Treating Anaphylaxis in Clinical Settings
Epinephrine, sometimes called adrenaline, is first-line treatment for anaphylaxis. Epinephrine affects the respiratory system by widening a patient’s airways, and the cardiovascular system by increasing his or her blood flow.
Epinephrine is dosed by body weight (0.3 mg/mL or 0.5 mg/mL is the average adult dose), which is why it’s important to choose an epinephrine delivery system that offers dosing flexibility (like EPIsnap®). Epinephrine should be readily available whenever patients are administered medication.
Some practitioners have suggested using antihistamines or corticosteroids as first-line treatment. This is not recommended because antihistamines take several hours to reach effective therapeutic levels and corticosteroids have no immediate effect.5 Antihistamines and corticosteroids may be useful as adjunctive therapy, after the initial crisis has subsided.
As a practitioner, it’s imperative that you have an anaphylaxis management protocol and that you familiarize yourself with it frequently. A patient can go from “symptom-free” to “dire distress” within seconds.
If you or your employer do not yet have a protocol, follow the World Allergy Organization’s published recommendations6 and be sure to monitor your patient’s blood pressure, cardiac rate and function, respiratory status, and oxygen levels once initial treatment is given.
The rate of anaphylaxis-related deaths is low but rising. Prompt treatment with epinephrine can minimize the chance of an anaphylactic event progressing to a fatality.
We’ve created an Anaphylactic Adverse Event Reporting Form to help you remember the details of an anaphylactic episode.
Sources
1 https://www.ncbi.nlm.nih.gov/pubmed/23352528
2 https://www.ncbi.nlm.nih.gov/pubmed/25280385
3 https://www.worldallergy.org/disease-focus/anaphylaxis – Guidelines
4 https://www.mayoclinic.org/first-aid/first-aid-shock/basics/art-20056620
5 https://emedicine.medscape.com/article/135065-treatment – d10
6 https://www.waojournal.org/content/4/2/13