Allergies can be diagnosed by an allergist using a skin test. These can detect hay fever, dermatitis, food allergies, and many other allergens depending on the severity of your condition. In order to prepare for a skin test, it is recommended that you do not consume any antihistamines within a specific amount of time prior to the test in order to receive the best results. You should also anticipate having a fairly decent-sized portion of your back available as this is where the skin prick test tends to take place. Up to 50 different substances can be tested at the same time with this method with very mild to no pain.
People can be affected by allergies in different ways and allergies are not a "one size fits all." There are food allergies, seasonal allergies, animals, dust, and so on. Sometimes you can just treat yourself with over the counter antihistamines but more severe cases will require you to see an Allergist or possibly an ENT.
So how do you know if it is a cold or flu and not allergies? Here are a few clues:
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