Allergic test is done, most of the time the eosinophil count, the absolute eosinophil count is done. If it is more than 400 or 500, it is a very significant number. Then person can be treated according to whatever the symptoms the person is having. If at all he is allergic rhinitis, then allergic rhinitis has to be treated, or the person is manifested just with a skin allergy, that is itching or rashes, that has to be treated accordingly. So it always depends, what is the allergy for and what are the patient symptoms.
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