The two sorts of allergy tests that are quite common are hair analysis and VEGA testing.

Hair analysis is what it says. Somebody sends off the hair and they do stuff with it and they come back with the report and is says you're allergic to X,Y and Z.

VEGA is where you hold electrodes - it's not harmful- they're not 1000 volts or anything- you hold electrodes, it's connected to a meter and then the practitioner puts different allergens on the skin and they look for the resistance.

There's no evidence that they give you a true picture of what your allergies are. They're also quite expensive and if you speak to your GP, he or she will be able to do the blood test quite easily and if you want the skin prick testing he or she can refer you to an allergy clinic where it can be done.