1 The symptoms of anaphylaxis may vary and can include hives, tongue swelling, vomiting, and even shock. 2  If someone is at risk, avoidance is the best form of treatment.  If one has a history of serious allergic reaction, he or she should always carry an epinephrine kit.
http://www.medicinenet.com/anaphylaxis/article.htm
1 Common triggers of an anaphylactic reaction include drugs, such as penicillin, insect stings, foods (peanuts, shellfish), X-ray dye, and latex. 2  The symptoms of anaphylaxis may vary and can include hives, tongue swelling, vomiting, and even shock.  If someone is at risk, avoidance is the best form of treatment.
http://www.medicinenet.com/anaphylaxis/article.htm
The most severe form is called anaphylaxis or anaphylactic shock. Allergic reactions occur more often in people who have a family history of allergies. Substances that don't bother most people (such as venom from bee stings and certain foods, medicines, and pollens) can trigger allergic reactions in certain people.
https://medlineplus.gov/ency/article/000005.htm
Certain people are more at risk of anaphylaxis. If you have allergies or asthma and have a family history of anaphylaxis, your risk is higher. And, if you’ve experienced anaphylaxis your risk of having another anaphylactic reaction is increased. Accurate diagnosis and successful management of allergies is essential.
http://www.aaaai.org/conditions-and-treatments/allergies/anaphylaxis
Severe anaphylactic reactions can be fatal. Anaphylaxis is often triggered by substances that are injected or ingested and thereby gain access into the bloodstream. This can result in a reaction involving the skin, lungs, nose, throat, and gastrointestinal tract.
http://www.medicinenet.com/anaphylaxis/article.htm
1 Anaphylaxis is the most severe allergic reaction and is potentially life threatening. 2  Anaphylaxis is rare. The vast majority of people will never have an anaphylactic reaction.  Common triggers of an anaphylactic reaction include drugs, such as penicillin, insect stings, foods (peanuts, shellfish), X-ray dye, and latex.
http://www.medicinenet.com/anaphylaxis/article.htm
Some reactions can occur after several hours, particularly if the allergen causes a reaction after it has been eaten. In very rare cases, reactions develop after 24 hours. Anaphylaxis is a sudden and severe allergic reaction that occurs within minutes of exposure.
https://medlineplus.gov/ency/article/000005.htm
Anaphylaxis (an-a-fi-LAK-sis) is a serious, life-threatening allergic reaction. The most common anaphylactic reactions are to foods, insect stings, medications and latex. If you are allergic to a substance, your immune system overreacts to this allergen by releasing chemicals that cause allergy symptoms. Typically, these bothersome symptoms occur in one location of the body. However, some people are susceptible to a much more serious anaphylactic reaction.
http://www.aaaai.org/conditions-and-treatments/allergies/anaphylaxis
1 Common triggers of an anaphylactic reaction include drugs, such as penicillin, insect stings, foods (peanuts, shellfish), X-ray dye, and latex.  The symptoms of anaphylaxis may vary and can include hives, tongue swelling, vomiting, and even shock.
http://www.medicinenet.com/anaphylaxis/article.htm
Allergic reactions are common. The immune response that causes an allergic reaction is similar to the response that causes hay fever. Most reactions happen soon after contact with an allergen. Many allergic reactions are mild, while others can be severe and life threatening.
https://medlineplus.gov/ency/article/000005.htm
what is anaphylaxis symptoms
Hives, tongue swelling, vomiting and even shock are symptoms of anaphylaxis. Symptoms of anaphylaxis are hives, tongue swelling, vomiting, and shock.