Identifying At-Risk Patients

Identifying At-Risk Patients

Identifying Patients at Risk for an Anaphylactic Reaction  

Major risk factors for a recurrent anaphylactic reaction include a history of previous anaphylaxis, exposure to triggers and atopy. The severity of previous reactions is not always indicative of the severity of future reactions, however.1-3

There are factors that increase the risk of anaphylaxis, such as exposure to known allergens, as well as factors that may increase the risk of a severe or fatal anaphylactic reaction, such as concomitant diseases and medications that hinder a patient from recognizing the signs and symptoms of anaphylaxis.4 A complete description of these risk factors can be found in Tables 1 and 2.

Table 1. Factors that increase the risk of experiencing anaphylaxis4


Exposure to certain allergens increases the risk of triggering an anaphylactic reaction for those who are allergic, including:

  • Foods such as peanuts, tree nuts, fish, shellfish, eggs and milk
  • Biting or stinging insects such as bees, ants and ticks
  • Latex
  • Medications such as β-lactam antibiotics (eg, penicillin)

Other factors

  • Exercise
  • Exposure to temperature extremes or UV radiation


Table 2. Factors that may increase anaphylaxis severity or risk of fatality4


  • Difficult to diagnose in infants due to similarities between symptoms and normal infant behaviors.
  • Adolescents and young adults may be at increased risk for more severe anaphylaxis because of inconsistent behaviors in avoiding their confirmed triggers.
  • The elderly may be at increased risk of fatal anaphylactic reactions because of concomitant diseases, including chronic obstructive pulmonary disease (COPD) and cardiovascular disease (CVD), and medications used to treat them. In addition, the elderly may be at an increased risk of having a more severe anaphylactic reaction if they are exposed to biting or stinging insects.


The following concomitant diseases are associated with an increased risk of a severe or fatal anaphylactic reaction:

  • Respiratory diseases such as asthma, especially if severe or uncontrolled
  • Chronic respiratory diseases such as COPD, especially if severe or uncontrolled
  • CVDs such as coronary heart disease and hypertension
  • Mastocytosis or clonal mast cell disorders
  • Atopic diseases (eg, allergic rhinitis, eczema)

In patients of any age, concomitant diseases hampering recognition of signs and symptoms of anaphylaxis may place patients at an increased risk of a more severe anaphylactic reaction. Such diseases include

  • Impaired vision or hearing
  • Neurologic disorders such as seizures
  • Psychiatric disorders such as depression
  • Autism spectrum disorder

Concurrent medication or chemical use

In patients of any age, concurrent medications and chemicals hampering recognition of signs and symptoms of anaphylaxis may place patients at an increased risk of anaphylaxis. Such medications and/or chemicals include:

  • First-generation H1-antihistamines such as diphenhydramine and chlorpheniramine
  • Antidepressants
  • Sedatives
  • Hypnotics
  • CNS-active chemicals such as ethanol
  • Recreational drugs

Medications that may increase the severity of anaphylactic reactions and make them more difficult to treat include:

  • β-blockers, which potentially decrease epinephrine efficacy by blocking effects at adrenergic receptors
  • Angiotensin-converting enzyme (ACE) inhibitors, which potentially interfere with endogenous compensatory responses


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.

For additional information please contact us at 800-395-3376.