Allergy

An allergy is something which triggers an allergic reaction. This is the immune system defending the body against attack by bacteria and viruses.

Sometimes the system goes wrong, and is triggered by some quite normal food, or flares up when the family pet comes into the room. This is what the ordinary person calls an 'allergy'.

Allergic reactions

When people come in contact with something they are allergic to, there can be many different reactions. These reactions include itchy eyes, drippy or stuffy noses, swollen faces, hives, sneezing, and coughing. If it is a food allergy, the person may get an upset stomach.

Sometimes a person's oesophagus, or throat, may swell up so much that the person can no longer breathe. This is called anaphylaxis. When this happens, a doctor must give the person a medicine called epinephrine to make the swelling go down. Some people with allergies to very common things, like bee stings or fish, carry this medicine with them so it can be used quickly in an emergency. The device they use to inject the medicine is called an epinephrine autoinjector.

Common allergies

Some common food allergies are:

• Nuts, especially peanuts
• Fish or shellfish
• Dairy products
• Eggs
• Soy products
• Wheat
• Fruits (kiwis and bananas, avocado)

Some common environmental allergies are:

• Latex - these allergies can overlap with fruit allergies, or develop through exposure to latex
• Pollen
• Ragweed
• Mold
• Furry pets
• Bee or wasp stings
• Dust mites
• Tobacco smoke
• Pollution

Drug allergies

This focuses mainly on severe allergic reactions to drugs. These are not all of the severe symptoms but it is helpful to be aware of signs appearing:

• lips, mouth, throat or tongue suddenly become swollen
• breathing very fast or struggling to breathe (someone may become very wheezy or it may feel like choking or gasping for air)
• the throat feels tight or there is struggling to swallow
• skin, tongue or lips turn blue, grey or pale (on black or brown skin, this may be easier to see on the palms of hands or soles of feet)
• suddenly becoming very confused, drowsy or dizzy
• someone faints and cannot be woken up

A child is limp, floppy or not responding like they normally do (their head may fall to the side, backwards or forwards, or they may find it difficult to lift their head or focus on your face)

You or the person who's unwell may also have a rash that's swollen, raised, itchy, blistered or peeling.

These can be signs of a serious allergic reaction and may need immediate treatment in hospital.

Related pages

• Histamine
• corticosteroids

References

• "Are you aware of your allergic symptoms?". Retrieved 28 November 2007.