Skin prick tests involve placing on your skin drops of extracts from things you may be allergic to.  We then scratch the skin through the drop. If you are allergic, a small red lump will form on your skin after a few minutes.  Don't worry - it goes away a few minutes later.

Skin tests are only of value if interpreted with respect to a careful history of a patient's clinical symptoms.  They are not a diagnosis by themselves, and should only be used after carefully listening to a patient's symptoms.

A negative skin test does not completely rule out allergy, but does make it much less likely.  A positive skin test does not prove allergy, but does make it more likely, and in some situations can provide the clinching piece of evidence for a diagnosis.