A 23-year-old woman comes to the emergency department less than an hour after being stung by a wasp. She has a history of asthma and felt some chest tightness soon after the sting. The patient administered 2 inhalations of her rescue albuterol, and her breathing subsequently improved. She also has generalized itching and crampy abdominal pain.
Blood pressure is 108/66 mm Hg, pulse is 94/min, respirations are 16/min, and SaO₂ is 95% on room air. The patient is breathing comfortably, without accessory muscle usage. Lung auscultation shows mild wheezing with good air entry. The abdomen is soft but mildly tender with slightly increased bowel sounds.
Which of the following is the most appropriate first step in management of this patient?

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Quizplus · Accepted Answer

11ec193a_96a2_c5d2_853d_5bf0a714939f_MD0002_00 This patient has had an allergic reaction to a wasp (hymenoptera) sting and has typical features of early anaphylaxis. Anaphylaxis is a severe allergic reaction characterized by skin and/or mucosal involvement associated with possible respiratory compromise, hypotension, and gastrointestinal distress. Common symptoms include wheezing, pruritus, rash, angioedema, headache, flushing, urticaria, and abdominal symptoms such as nausea, vomiting, diarrhea, cramps, and bloating. Initial symptoms of anaphylaxis may be subtle and relatively minor but can progress rapidly to life-threatening respiratory and cardiovascular collapse. Guideline statements recommend use of intramuscular epinephrine as the first-line therapy to treat severe allergic reactions and anaphylaxis. Epinephrine reduces airway compromise and can prevent or treat anaphylactic shock. There are no absolute contraindications to epinephrine use in anaphylaxis, and it is advised even for patients with mild to moderate clinical features. Unstable patients will also require aggressive fluid resuscitation and airway management. All patients with anaphylaxis should be prescribed auto-injectable epinephrine and referred to an allergist on discharge. (Choice A) Observation is appropriate to monitor for severe allergy in patients who have been exposed to possible allergens (eg, influenza vaccine given to a patient with egg allergy). However, observation alone would be inappropriate in this patient given her early signs of anaphylaxis. (Choice B) Antihistamines are useful in treating the skin symptoms of anaphylaxis but do not address the respiratory or cardiovascular manifestations. (Choice D) Systemic glucocorticoids may help treat bronchospasm and are often recommended to prevent rebound anaphylaxis. However, onset of action is slow, and a recent review found no randomized controlled trials to support the use of glucocorticoids for anaphylaxis. (Choice E) Albuterol can be used to treat residual wheezing after epinephrine administration. However, albuterol does not treat the associated airway edema, which requires epinephrine. Educational objective: Anaphylaxis can present with relatively mild manifestations but progress to life-threatening disease. Skin findings, respiratory compromise, hypotension, or gastrointestinal symptoms after exposure to an allergen suggest anaphylaxis. Intramuscular epinephrine is recommended for all patients with features of anaphylaxis. __________ References: Epinephrine: the drug of choice for anaphylaxis. A statement of the World Allergy Organization. (http://www.ncbi.nlm.nih.gov/pubmed/18691308) Anaphylaxis: recognition and management. (http://www.ncbi.nlm.nih.gov/pubmed/22085665)

A 23-Year-Old Woman Comes to the Emergency Department Less Than