Content Reviewers:Antonella Melani, MD, Lisa Miklush, PhD, RNC, CNS, Jannah Amiel, MS, BSN, RN, Jodi Berndt, PhD, RN, CCRN-K, PCCN-K, CNE, CHSE, Gabrielle Proper, RN, BScN, MN
Jocelyn Williams is a 18-year-old female client with a history of severe peanut allergy who is brought to the emergency department, or ED, via paramedics after accidentally eating a cookie that contained peanuts.
Her initial vital signs were tympanic temperature 98.7 F or 37 C, heart rate 126 beats per minute, respiratory rate 32 breaths per minute with audible wheezing, blood pressure 96/60, and SpO2 87% on room air.
These include antigens found in certain foods like peanuts, eggs, and shellfish, as well as venom from insect bites or bee stings.
In addition, some clients can develop allergic reactions when exposed to latex or radiocontrast agents used for imaging techniques like a CT scan or MRI.
Later on, if the same person gets stung by a bee again, their mast cells and basophils, which already have IgE antibodies on their surface, are able to recognize the antigens and release their proinflammatory molecules, triggering an allergic reaction.
In most cases, this would cause some localized damage, like a swelling around the sting site, but sometimes things get really serious, and there’s massive release of proinflammatory molecules into the bloodstream.
When the allergic reaction involves two or more organ systems, such as the cutaneous, respiratory, cardiovascular, and gastrointestinal systems, it’s called anaphylaxis.
Now, there are some factors that may put the client at risk of anaphylaxis, such as atopy, which means having a genetic predisposition to allergic reactions, including allergic rhinitis, asthma, and atopic dermatitis.
Other risk factors include having a personal or family history of anaphylaxis. Symptoms of anaphylaxis typically start right after exposure to the antigen, and usually peak within 30 minutes.
Angioedema is often associated with cutaneous manifestations like urticaria, which presents with a skin rash and pruritus, as well as flushing of the skin.
In some cases, the massive release of proinflammatory molecules can lead to widespread vasodilation, which results in severe hypotension.
If blood pressure gets so low that it can’t supply vital organs, like the heart or brain, it’s called anaphylactic shock.
Reduced blood supply to the heart could cause myocardial infarction, especially in clients who already have an underlying heart disease, while reduced blood supply to the brain can cause loss of consciousness. Finally, if not promptly treated, anaphylaxis can lead to death.
Diagnosis of anaphylaxis is typically based on history and physical examination, as well as identifying a likely exposure and trigger.
One way to identify an allergic trigger is through skin prick tests, where small drops of allergens are pricked into the skin with a tool, to see if there’s evidence of an allergic reaction, like raised, itchy, red bumps or weals. Finally, specific lab tests like histamine and IgE levels are usually elevated.
Now, anaphylaxis is a medical emergency that needs immediate treatment, starting by ensuring a patent airway.