Allergy: A hypersensitivity of the body's immune system in response to exposure to specific substances (antigens), such as pollen, beestings, poison ivy, drugs, or foods. Anaphylactic shock is a severe form of allergy response which is a medical emergency. Symptoms of anaphylactic shock include dizziness, loss of consciousness, labored breathing, swelling of the tongue, blueness of the skin, low blood pressure, and death.
Anaphylaxis: Severe allergic response to a substance. Symptoms include wheezing, itching, nasal congestion, hives, immediate intense burning of hands and feet, collapse with severe drop in blood pressure, loss of consciousness and cardiac arrest. Symptoms of anaphylaxis appear within a few seconds or minutes after exposure to substance causing reaction; this can be medication or herbs taken by injection, by mouth, vaginally, rectally, through a breathing apparatus or applied to skin. Anaphylaxis is an uncommon occurrence, but when it occurs, it is a MEDICAL EMERGENCY! Without appropriate immediate treatment, it can cause death. Yell for help. Don't leave the victim. If the person is found without any response and has no pulse begin CPR (cardiopulmonary resuscitation), have someone dial "0" or 911, if you are living in the United States. In India, you can dial 108. Don't stop CPR until help arrives.
Hives (urticaria): Elevated patches on skin usually caused by an allergic reaction accompanied by the release of histamine into body tissues. Patches are redder or paler than the surrounding skin and itch intensely.