Allergy is a kind of hypersensitivity or reaction of the body to the external substances which may or may not be otherwise harmful. A healthy body is guarded against the invasion of germs by certain special cells which are collectively called the immune system. As a reaction to any foreign body, an antibody is produced inside the individual which envelops and destroys the former. Sometimes this immune system over reacts to some apparently harmless substances such as pollen, pieces of hair, dust particles and even perfume.
Diagnosis:
There are numerous methods for the evaluation and diagnosis of allergies. They include, but are not limited to:
- Skin Test
- Total IgE Count
Skin Test:
Skin testing is the most simple and typical method of diagnosing Type 1 Hypersensitive. Skin test is also known as prick testing due to the series of pricks made into the patient’s skin. Here is how this test is performed;
Small amounts of suspected allergens and/or their extracts are either injected intradermally or into small scratchings made into the patient’s skin, often with a lancet. If the patient is allergic to the substance, within 30 minutes a visible inflammatory reaction can be observed on to the skin in any form ranging from slight reddening of the skin to full-blown hives.
There are problems associated with this test. They are:
- Delayed-type hypersensitivity or DTH
- Inception of new allergy due to the application of previously unencountered allergens
- Inability of the patient to react to the skin test allergens makes skin tests not always able to pinpoint a patient’s specific allergies
Total IgE Count:
This method is used for measuring the amount of serum IgE contained within the patient’s serum. Colormetric immunoassays and radiometric can be used to determine this. Radioallergosorbent or RAST can help measure even the levels the amount of IgE specific to certain allergens. |
