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Anaphylaxis is an extremely rare and life-threatening allergic reaction. Symptoms often appear immediately after exposure to the substance that is causing the reaction.

Possible Allergy Symptoms:

  • Itching, hives, redness, swelling, or a burning or stinging sensation
  • A drop in blood pressure, light-headedness, loss of consciousness, slurred speech
  • Difficulty breathing (or the inability to breathe), difficulty breathing, allergy cough, wheezing
  • Nausea, cramping, vomiting, or diarrhea

We want to reiterate that anaphylaxis is rare. Most people who suffer from allergies will never experience an anaphylactic reaction.


Most anaphylactic reactions occur after eating or drinking a particular food, taking certain medication, or after an insect sting.  In rare cases, anaphylaxis can occur after being exposed to the cold or after exercising.  Still others have experienced anaphylaxis for no identified cause.



  • Insect stings: bee, wasp, yellow jacket, or hornet
  • Allergy testing extracts used for diagnosis and treatment of allergic conditions
  • Antibiotics such as penicillin

Swallowing, even just a tiny bite
Inhalation – incredibly rare
Skin contact
Latex gloves

Food ingestion is the most common cause of anaphylaxis, with nuts (especially peanuts) and seafood being the most common triggers.  Cow’s milk allergy and egg allergy are also common triggers in children.  Most life-threatening anaphylactic reactions occur when a patient has eaten food that has an unknown ingredient in it.  For example, some chili recipes contain peanuts as a thickener.

For some patients, anaphylaxis involves two or more factors. Someone may experience anaphylaxis if they eat a specific food, and then exercise shortly after.  Alone, neither the exercise nor the food causes any reaction in these people. Allergy testing at our allergy clinic will help find the causes of these allergic reactions.


Anaphylactoid reactions resemble anaphylactic reactions but involves no real allergy.  The symptoms will be similar but caused by different biological processes.  Fortunately, the treatment is the same for both.  Unlike most anaphylactic reactions, anaphylactoid reactions can occur with no previous exposure at all.   Both radiographic contrast agents (the dyes that allow physicians to see your veins and arteries on an x-ray) and morphine are known to cause anaphylactoid reactions, but these reactions are uncommon.


The first step in preventing anaphylaxis is avoiding the allergen(s) that cause you to react. This is often a challenge because you can unknowingly come into contact with an allergen.  Your NY dr will have ideas to help you avoid your triggers. Allergy tests are an important way of determining what you are allergic to.

Immunotherapy (“allergy shots”) are another treatment option that can help reduce your risk of a reaction and/or minimize the reaction.  Allergy immunotherapy is a very effective, natural protection for insect stings (wasp, bee, yellow jacket, and hornet) but is not practical or available for all triggers. Immunotherapy has some risk involved, but our allergists are experienced specialists that work in a controlled setting and can minimize the risk.

If someone is allergic to penicillin, a good way to prevent a future reaction is to use an alternative antibiotic to treat the patient’s illness.  Our allergists may want to do an allergy test to confirm that you have a penicillin allergy. Usually our NYC doctors will ask you avoid penicillin and its derivatives. However, sometimes penicillin is the most effective antibiotic for a specific illness.  If so, there are treatment options that can temporarily desensitize you to penicillin so that your doctor (perhaps your ear, nose, and throat doctor) can use it to treat your specific condition at a particular time.


Epinephrine is the prescription medication that is used to treat anaphylaxis.  It is fast-acting and is administered by injection. If you have experienced an anaphylactic reaction in the past, we recommend that you carry epinephrine with you at all times.  For individual use, pre-filled syringes that are designed for self-injection can be purchased with a prescription from your New York doctor.   It is important that you are trained by an allergist about when and how to use epinephrine.

Some medications for high blood pressure (“beta blockers”) counteract epinephrine, making it more difficult to treat you if you experience anaphylaxis.  Therefore, if you on beta blockers and you are a highly-allergic person (or have a history of anaphylaxis), your doctor may want to consider other options for treating your high blood pressure.

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If you are worried about anaphylaxis, the allergy specialists and doctors at the NY Allergy & Sinus Centers would like to help.  We have the latest treatment & testing, and convenient clinics throughout New York City: Murray HillMidtownUpper West SideChelsea, and Queens. Call us at 212-686-4448 for an appt. We see pediatric and adult patients from all over the NYC metropolitan area: Manhattan, Brooklyn, Queens, Staten Island, and the Bronx.