Anaphylaxis occurs when the immune system overreacts to a harmless substance, called an allergen. The immune system is made up of special cells, called white blood cells, which fight infection. When an allergen is present in the body, white blood cells recognize the allergen, and release chemicals into the blood stream. These chemicals can cause inflammation of the skin, nose, throat, lungs or intestines.

Organ Systems Affected in Anaphylaxis

Organ System	Typical Symptoms and Findings
Skin	hives, swelling, itching
Cardiovascular	dizziness, weakness, fainting, chest pain, shock
Lungs	choking, hoarseness, difficulty breathing, wheezing
Gastrointestinal	nausea, vomiting, diarrhea, cramps
Neurologic	headaches, seizures

Substances that trigger allergic reactions include:

• Blood transfusion allergic reaction
• Dust mites
• Dyes used for imaging tests
• Exercise
• Exposure to cold
• Exposure to heat
• Insect bites and stings
• Latex gloves allergy
• Mold
• Pet dander
• Pollens
• Soaps, lotions, and detergents
• Sunlight
• Vaccines
• Vitamins
• Food additives:
• Sulfite allergy
• Tyramine allergy
• Tartrazine allergy
• Monosodium glutamate allergy
• Food allergies:
• Egg allergy
• Fruits
• Nuts
• Shellfish allergy
• Medication allergies:
• Antibiotic allergies
• Anti-inflammatory medication
• Aspirin