If anaphylaxis is suspected, take the following steps:
Rapidly assess airway, breathing, circulation, and mentation (mental activity).
Call for emergency medical services (EMS).
Place the patient in a supine position (face up), with feet elevated, unless upper airway obstruction is present or the patient is vomiting.
Epinephrine (1 mg/ml aqueous solution [1:1000 dilution]) is the first-line treatment for anaphylaxis and should be administered immediately.
In adults, administer a 0.3 mg intramuscular dose using a premeasured or prefilled syringe, or an autoinjector, in the mid-outer thigh (through clothing if necessary).
The maximum adult dose is 0.5 mg per dose.
Epinephrine dose may be repeated approximately every 5-15 minutes if symptoms do not improve or if they return while waiting for EMS. The number and timing of epinephrine doses should be recorded and communicated to EMS.
Because of the acute, life-threatening nature of anaphylaxis, there are no contraindications to epinephrine administration.
Antihistamines (e.g., H1 or H2 antihistamines) and bronchodilators do not treat airway obstruction or hypotension and, thus, are not first-line treatments for anaphylaxis. However, they can help provide relief for hives and itching (antihistamines) or symptoms of respiratory distress (bronchodilators) but in a patient with anaphylaxis should only be administered after epinephrine. Administration of antihistamines to COVID-19 vaccine recipients prior to vaccination to prevent allergic reactions is not recommended. Antihistamines do not prevent anaphylaxis, and their prophylactic use may mask cutaneous symptoms, which could lead to a delay in the diagnosis and management of anaphylaxis.
Because anaphylaxis may recur after patients begin to recover, monitoring in a medical facility for at least four hours is advised, even after complete resolution of symptoms and signs.
Considerations for anaphylaxis management in special populations
Older adults, including long-term care facility residents
There are no contraindications to the administration of epinephrine for the treatment of anaphylaxis. Although adverse cardiac events, such as myocardial infarction or acute coronary syndrome, have been reported in some patients who received epinephrine for treatment of anaphylaxis (particularly among older adults with hypertension and/or atherosclerotic heart disease), epinephrine is the first-line treatment for anaphylaxis. It is important that locations providing vaccination to older adults, including long-term care facility residents, have staff members available who are able to recognize the signs and symptoms of anaphylaxis. This will help not only to ensure appropriate and prompt treatment for patients with anaphylaxis, but also to avoid unnecessary epinephrine administration to patients who do not have anaphylaxis.
Pregnant people with anaphylaxis should be managed the same as non-pregnant people. As with all patients with anaphylaxis, they should be transported to a medical facility where they and their fetus can be closely monitored to ensure adequate perfusion.
Homebound people requiring home vaccination services
Homebound people who might be at increased risk for anaphylaxis following vaccination (i.e., people with a precaution to vaccination or those with a history of anaphylaxis due to any cause) should consider whether they could be vaccinated in a setting where medical care is immediately available if they experience anaphylaxis following vaccination. If home vaccination is the only option for these people and, through risk assessment, it is determined that the benefits of vaccination outweigh the potential risk for anaphylaxis, home vaccination providers should ensure they are able to manage anaphylaxis. This includes appropriate screening; post-vaccination observation; medications and supplies; staff qualifications for recognition and treatment of anaphylaxis; ability to call for EMS; and location in an area where EMS is available.
Patients who experience a severe allergic reaction (e.g., anaphylaxis) or an immediate allergic reaction (i.e., hypersensitivity-related signs or symptoms consistent with urticaria, angioedema, respiratory distress, or anaphylaxis that occur within four hours following administration) of any severity after a dose of a COVID-19 vaccine should be instructed not to receive additional doses of the vaccine; if the dose received was an mRNA COVID-19 vaccine, the patient should not receive additional doses of either Pfizer-BioNTech or Moderna COVID-19 vaccine. In addition, patients may be referred to an allergist-immunologist for appropriate work-up and additional counseling.
Report any adverse events, including anaphylaxis, that occur in a recipient following COVID-19 vaccination, to the Vaccine Adverse Event Reporting System (VAERS). Vaccination providers administering a COVID-19 vaccine that is under Emergency Use Authorization are required by the Food and Drug Administration to report vaccine administration errors, serious adverse events, cases of Multisystem Inflammatory Syndrome, and cases of COVID-19 that result in hospitalization or death. Reporting is also encouraged for any other clinically significant adverse event, even if it is uncertain whether the vaccine caused the event. Refer to the VAERS website or call 1-800-822-7967for more information on how to submit a report to VAERS. In addition, CDC has developed a new, voluntary, smartphone-based tool, called “v-safe,” that uses text messaging and web surveys to provide patients with near real-time health check-ins after they receive a COVID-19 vaccination. CDC/v-safe call center representatives will follow up on reports of medically significant health impacts to collect additional information and complete a VAERS report. Learn more about v-safe on CDC’s website.