What are the symptoms of an allergic reaction?

Dr. Kathleen Handal, MD
Emergency Medicine Specialist

The signs and symptoms of an allergic reaction are:

Mild reaction:

  •  itching, raised red skin rash, hives
  •  itching around eyes
  •  swelling at a bite/sting mark
  •  stuffy nose, sneezing

Severe reaction:

  • swelling of the throat, face and eyes
  • difficulty breathing
  • fainting and shock
  • loss of consciousness
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Symptoms of a mild allergic reaction include tingly lips and tongue, feeling sick, stomach pain, runny nose and watering eyes, and an itchy rash on the skin called hives.

In a severe allergic reaction, called anaphylaxis, the symptoms can make people feel very sick. Histamine lets the fluids leak out of your blood vessels, which can make you feel dizzy and might even make you pass out. It also causes the muscles in your airway to tighten, making it difficult to breathe.

The body's first line of defense against potentially dangerous invaders includes the mouth, eyes, lungs, stomach and nose. When your immune system reacts to an allergen, these body parts can potentially become battlegrounds.

Signs of the raging battle can include one or more of these conditions: sneezing; watery, swollen or red eyes; nasal congestion; sinus inflammation and pressure; runny nose; hives; rashes; itchy eyes; itchy nose; shortness of breath; a tight feeling in the chest; difficulty breathing; wheezing; coughing; nausea; headache; fatigue; diarrhea; and, of course, a general feeling of misery.

It's ironic that your immune system, which is designed to defend you from illnesses, produces symptoms that make you feel sick when it overreacts to such mundane substances as dust and pollen. It's a perfect example of the old saying, "Sometimes the cure is worse than the disease."

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.