Common Causes of Anaphylaxis

Common Causes of Anaphylaxis

Allergens that induce anaphylaxis include food, biting or stinging insects, medications and latex; however, anaphylaxis is occasionally reported after direct exposure to radiocontrast media and can also occur after exercise (Table 1).1-3

Table 1. Causes of anaphylaxis1-3


  • Peanuts
  • Tree nuts (eg, walnuts and pecans)
  • Fish
  • Shellfish
  • Cow’s milk
  • Soy
  • Eggs

Biting or stinging insects

  • Stinging insects (eg, honeybees, fire ants, yellow jackets, yellow hornets and paper wasps)
  • Less commonly, biting insects (eg, mosquitoes, ticks and flies)


  • β-lactams (eg, penicillin)
  • Nonsteroidal anti-inflammatory drugs (NSAIDs) (eg, aspirin and ibuprofen)5
  • Biologic modifiers (eg, cetuximab, infliximab and omalizumab)3

Natural rubber latex


Radiocontrast media§

*Peanuts, tree nuts, fish, shellfish, milk and eggs account for the greatest number of anaphylactic reactions in children; shellfish is the most common trigger in adults.6

Anaphylactic reactions induced by biting or stinging insects are more common in adults than in children.7

Anaphylaxis in response to a medication can occur in patients of any age, but is particularly common in middle-aged and older adults.5

§In some people exercise and exposure to radiocontrast cause non-immune perturbations of mast cells and basophils leading to anaphylaxis.1

A diagnosis of idiopathic anaphylaxis is made when no triggers can be identified based on history, negative skin tests, and absent or undetectable serum-specific IgE levels. Every possibility of a hidden or previously unrecognized trigger should be ruled out before a diagnosis of idiopathic anaphylaxis is made.1-3

Certain risk factors may increase the likelihood and severity of an anaphylactic reaction1 and are discussed in the “Identifying At-Risk Patients” section.



EpiPen® (epinephrine) 0.3 mg and EpiPen Jr® (epinephrine) 0.15 mg Auto-Injectors are indicated in the emergency treatment of type 1 allergic reactions, including anaphylaxis, to allergens, idiopathic and exercise-induced anaphylaxis, and in patients with a history or increased risk of anaphylactic reactions. Selection of the appropriate dosage strength is determined according to body weight.

Important Safety Information

EpiPen Auto-Injectors should only be injected into the anterolateral aspect of the thigh. DO NOT INJECT INTO BUTTOCK, OR INTRAVENOUSLY.

Epinephrine should be used with caution in patients with certain heart diseases, and in patients who are on drugs that may sensitize the heart to arrhythmias, because it may precipitate or aggravate angina pectoris and produce ventricular arrhythmias. Arrhythmias, including fatal ventricular fibrillation, have been reported in patients with underlying cardiac disease or taking cardiac glycosides or diuretics. Patients with certain medical conditions or who take certain medications for allergies, depression, thyroid disorders, diabetes, and hypertension, may be at greater risk for adverse reactions. Other adverse reactions include transient moderate anxiety, apprehensiveness, restlessness, tremor, weakness, dizziness, sweating, palpitations, pallor, nausea and vomiting, headache, and/or respiratory difficulties.

EpiPen and EpiPen Jr Auto-Injectors are intended for immediate self-administration as emergency supportive therapy only and are not intended as a substitute for immediate medical or hospital care.

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit or call 1-800-FDA-1088.

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