Medically reviewed by
Richard P. Silton, MD
Most have heard of allergic reactions, but few understand the characteristics of the most serious and life-threatening allergic reaction known as anaphylaxis. According to the Asthma and Allergy Foundation of America (AAFA), anaphylaxis is a common occurrence in the United States. This life-threatening allergic reaction was found to be present in about one of every 50 people. However, many experts think this number could actually be even higher with closer to one in 20 people suffering from the condition.
What is anaphylaxis?
Anaphylaxis is a severe and potentially life-threatening allergic reaction that is both quick and severe. It can occur within just minutes, or even seconds, after you’ve been exposed to the substance that you’re allergic to like a bee sting, latex, or peanuts. During anaphylaxis, your body’s immune system goes into overdrive, releasing a wave of chemicals that could cause you to go into shock. During this time, your blood pressure decreases, your pulse weakens, and your airways narrow so your breathing becomes blocked. Nausea, vomiting, and skin rash can also occur.What causes anaphylaxis?
Anaphylaxis, as well as allergies in general, occurs when the body overreacts to an allergen. When the body is exposed to an allergen, it responds by producing histamine and other chemicals causing your blood vessels to dilate. This allows more fluid to enter your tissues and causes swelling. During anaphylaxis, these chemicals are released throughout the whole body and can cause low blood pressure, hives, and difficulty breathing. This reaction occurs as a result of your immune system, which is designed to protect you when you are exposed to foreign substances. Your body produces antibodies that are recognized the next time you are exposed to that trigger. That is why Anaphylactic shock doesn’t always happen the first time you are exposed to an allergen, but may occur the next time you come in contact with the allergen.What are some common causes of anaphylaxis?
Food allergies are the most common cause of anaphylaxis. Some prevalent triggers include:- shellfish
- nuts
- milk
- eggs
- fish
- some fruits
What is idiopathic anaphylaxis?
Idiopathic anaphylaxis is the name given by the medical field when the cause for the allergic reaction isn’t known. Regardless, the symptoms are often the same and signal a medical emergency. During idiopathic anaphylaxis, you could experience wheezing or other breathing problems, your airway could be partially blocked because your tongue is swollen, and you could have problems swallowing. You might have a rash or hives and you could even experience dizziness or pass out. Though it is not clearly understood, there is a significant number of people who have idiopathic anaphylaxis whose condition gradually improves. Even if you have severe symptoms that are life-threatening, you might notice that you have fewer reactions over time. It might surprise you to learn that anaphylactic reactions can vary widely from one person to another. You might even experience different variations in regards to the severity of your reactions, and the reactions themselves. While your symptoms might worsen quickly at first, they might stay at the same severity level for quite some time before going away by themselves. Your symptoms could occur one after the other, alone, or all at the same time. Even if they have been treated, the symptoms could reappear once again in 24 hours.What are the signs and symptoms of anaphylaxis?
At first, it might not be obvious to you, and those around you, that you are having an anaphylactic reaction. Typically, the first signs — a skin rash or runny nose, for example — mimic those of an allergic reaction. Within about 30 minutes, however, you might see at least two of the following symptoms appear:- swollen or itchy tongue and/or lips
- paleness
- rash, hives, itchy, red or swollen skin
- weak pulse
- confusion, dizziness, fainting or weakness
- cramps, diarrhea or vomiting
- sneezing, runny or stuffy nose
- chest tightness
- rapid heartbeat
- itching
- hoarse voice, trouble swallowing, throat tightness
- wheezing, pain, coughing
- itchy or swollen throat
- Grade 1 symptoms typically involve the skin and can include skin rash, itching, swelling of the skin, and hives.
- Grade 2 symptoms include the signs from Grade 1 and also involve other systems. For example, you might experience a runny nose, hoarseness, and difficulty breathing. You could have cramping and vomiting, as well as low blood pressure, fast pulse, and an irregular heartbeat.
- Grade 3 symptoms include diarrhea, bloating, and the urge to have a bowel movement. Your skin and mucous membranes might take on a bluish tinge and you could have breathing difficulties. Because your body is not able to get enough blood to your organs, you could go into shock and lose consciousness.
- Grade 4 symptoms can include all of those mentioned above as well as respiratory arrest in which you stop breathing. You could also experience circulatory arrest during which the blood stops circulating throughout your body.