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Allergic Reaction (cont.)

What Are Symptoms and Signs of an Allergic Reaction?

The look and feel of an allergic reaction depends on the body part involved and the severity of the reaction. Some reactions may be localized and limited, while others could involve multiple body systems. Reactions to the same allergen vary among individuals.

  • Anaphylaxis is the term for any combination of allergic symptoms that is rapid, or sudden, and potentially life-threatening. Call 9-1-1 or activate emergency medical services immediately for suspected anaphylaxis.
    • One sign of anaphylaxis is shock. Shock has a very specific meaning in medicine. Shock may lead rapidly to death. The organs of the body are not getting enough blood because of dangerously low blood pressure. The person in shock may be pale or red, sweaty or dry, confused, anxious, or unconscious.
    • Breathing may be difficult or noisy, or the person may be unable to breathe.
  • Shock is caused by sudden dilation of the blood vessels. This is brought on by the action of the mediators. If the drop in blood pressure is sudden and drastic, it can lead to unconsciousness, even cardiac arrest and death.
  • Symptoms and signs of an allergic reaction include any, some, or many of the following:
    • Skin: irritation, redness, itching, swelling, blistering, weeping, crusting, rash, eruptions, or hives (itchy bumps or welts)
    • Lungs: wheezing, tightness, cough, or shortness of breath
    • Head: swelling or bumps on the face and neck, eyelids, lips, tongue, or throat, hoarseness of voice, headaches
    • Nose: stuffy nose, runny nose (clear, thin discharge), sneezing, postnasal drip
    • Eyes: red (bloodshot), itchy, swollen, or watery or swelling of the area around the face and eyes
    • Stomach: pain, nausea, vomiting, diarrhea, or bloody diarrhea
    • Other: fatigue or feeling tired, sore throat, dizziness, or lightheadedness
Last Reviewed 9/11/2017

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