When the immune system incorrectly reacts to a substance that is harmless, such as a bug bite, it will release histamine and other chemicals that can cause symptoms that are sometimes life-threatening. Anaphylactic shock is also referred to as anaphylaxis. It is a severe allergic reaction that requires medical attention immediately.
Symptoms can include:
Rash or hives
Pale skin
Breathing problems
Rapid pulse
Although uncommon in children under six months of age, anaphylactic shock can happen to any child. There are a number of things that can cause anaphylactic shock in children; foods like peanuts, milk, eggs; drugs such as penicillin and amoxicillin; bug bites or stings; and certain industrial substances like latex.
If your toddler show serious signs of anaphylactic shock like trouble breathing, rapid pulse, or fainting, rush them to the hospital or call emergency services right away.  Lie your child down and elevate their feet, and do not attempt to feed your child anything.

If your toddler ever develops anaphylactic shock, they should wear a medical alert bracelet which will inform doctors of her condition if there is an emergency. You should also advise her preschool or child minder of her condition and what they should do if she shows any symptoms.