Signs and symptoms of a severe allergic reaction can occur within minutes of exposure to an allergen. In rarer cases, the time frame can vary up to several hours after exposure. The ways these symptoms occur can vary from person to person and even from episode to episode in the same person.
Symptoms of anaphylaxis generally include two or more of the following body systems: skin, respiratory, gastrointestinal and/or cardiovascular. However, low blood pressure alone (i.e. cardiovascular system), in the absence of other symptoms, can also represent anaphylaxis.
- Skin: hives, swelling (face, lips, tongue), itching, warmth, redness.
- Respiratory (breathing): coughing, wheezing, shortness of breath, chest pain or tightness, throat tightness, hoarse voice, nasal congestion or hay fever-like symptoms (runny, itchy nose and watery eyes, sneezing), trouble swallowing.
- Gastrointestinal (stomach): nausea, pain or cramps, vomiting, diarrhea.
- Cardiovascular (heart): paler than normal skin color/blue color, weak pulse, passing out, dizziness or lightheadedness, shock.
- Other: anxiety, sense of doom (the feeling that something bad is about to happen), headache, uterine cramps, metallic taste.
Because of the unpredictability of reactions, early symptoms should never be ignored, especially if the person has suffered an anaphylactic reaction in the past.
It is important to note that anaphylaxis can occur without hives.If an allergic person expresses any concern that a reaction might be starting, the person should always be taken seriously. When a reaction begins, it is important to respond immediately, following instructions in the person’s Anaphylaxis Emergency Plan. The cause of the reaction can be investigated later. The most dangerous symptoms of an allergic reaction involve
breathing difficulties caused by swelling of the airways (including a severe asthma attack in those who have asthma) or
a drop in blood pressure indicated by dizziness, lightheadedness, feeling faint or weak, or passing out. Both can lead to death if untreated.
