Anaphylaxis is a severe inflammatory allergic reaction that can be life-threatening and which needs immediate emergency medical treatment. It is commonly caused by allergies to foods, drugs or stinging insects. Its symptoms include:

• itching;
• weals on the skin;
• bronchospasm (when the airways in the lung constrict, which causes breathing difficulties similar to an asthma attack);
• low blood pressure;
• abdominal cramps; and
• collapse.

If anaphylaxis occurs, eye symptoms are often experienced as well. These include:

• gross swelling of the soft tissue around the eye; and
• redness, swelling and itching of the conjunctiva.

In some people, ingesting certain preservatives such as monosodium glutamate (MSG) or sodium metabisulphite causes swelling and redness of the eye. However, ingesting these preservatives may not cause the severe bodily symptoms to the extent usually seen in anaphylaxis.

If you suspect someone is experiencing anaphylaxis you should call a doctor or ambulance immediately.