Symptoms of anaphylaxis generally occur immediately after exposure to the allergen to which the person is sensitive. However, it can take as long as several hours after exposure before signs of anaphylaxis appear. The more rapidly symptoms appear, the more severe they are likely to become.

Symptoms of an anaphylactic reaction can affect many different parts of the body. Early signs and symptoms include:

Lungs

• Shortness of breath
• Choking or difficulty breathing
• Coughing
• Wheezing
• Chest pain or tightness

Skin

• Hives (including on the lips, eyelids, throat and tongue)
• Skin rash
• Bluish tint to skin (cyanosis), including lips or nail beds
• Swelling
• Generalized itch
• Redness
• Warmth
  

Stomach

• Abdominal cramps
• Diarrhea
• Nausea
• Vomiting

Other

• Severe itching of the eyes, mouth or throat
• Feeling anxious
• Palpitations (an awareness of a strong, fast, irregular, abnormal or “galloping” heartbeat)
• Slurred speech
• Inability to swallow
• Swelling of the throat or tongue
• Tightness in the throat
• Hoarseness
• Rapid or weak pulse
• Dizziness
• Low blood pressure
• Nasal congestion
• Headache
• Uterine cramps

Most cases of anaphylaxis involve cardiovascular and/or respiratory symptoms. The pattern of symptoms also typically remains the same for an individual from episode to episode. However, subsequent reactions can be more severe than the first. Without immediate emergency treatment, anaphylaxis can quickly progress to anaphylactic shock and become deadly. More advanced symptoms include:

• Collapse or loss of consciousness
• Convulsions
• Loss of bladder control
• Shock
• Stroke
• Cardiac arrest
• Respiratory arrest

Those who experience an anaphylactic reaction are in life-threatening danger and need immediate medical attention. Individuals should use epinephrine at the first sign of an anaphylactic reaction and then call an ambulance for additional medical treatment.  For more information, see Treatment options.