In the allergy skin test, the skin is exposed to various suspected allergens to gauge the body’s reaction to those substances. The aim of the allergy test is not only to indentify the allergen but also to help the health care giver devise an effective treatment plan that may include medications or allergy shots and effective ways to avoid allergens.
When the allergy skin test is used and when it is not indicated
Allergy skin tests are an accurate and easy way to determine what one is allergic to and severity of the allergies. This helps one devise effective strategies for responding to and controlling the allergic reaction.
Air-borne allergens like dust, pet dander and pollen can be identified by skin test allergies.
Food allergies, allergic rhinitis, eczema, latex allergy, bee venom allergy or certain drug allergies can be identified by the help of allergy skin tests.
These are safe and possible for people of any age except those whose allergies are so extreme as to produce a life threatening reaction even when exposed only to tiny amounts of allergen.
If a person has certain skin conditions such as cutaneous mastocytosis, dermographism, extensive psoriasis or eczema or if they are on certain types of medications that could interfere with test results, the allergy skin test is not indicated.
When it is not possible to administer skin test allergies, blood tests can be conducted to indentify allergies. However these can be more expensive and less accurate so skin allergy tests are the most preferred methods of indentifying allergens and noting the extent of the person’s reaction to them; i.e. the severity of the allergy.
What can you expect when undergoing an allergy skin test
There is little or no preparation required from the patient when undergoing an allergy skin test and the person may rest assured that the there is little pain or discomfort suffered. The fact that the test is performed in a controlled manner in the presence of experts means that any adverse reactions can be controlled.
Before the test is administered, the doctor should be told if one is on any medication. If there are any family members who have allergies this should be told. Information about how the person reacts to what stimuli and the severity of the symptoms should also be provided.
There are three main types of skin allergy tests
The scratch (prick or puncture) test is conducted by introducing a tiny portion of the allergen into the outer layer of skin. The area is first cleaned and then marked to indicate which allergen is deposited in which area of the skin.
The intradermal or the skin point titration test uses a very dilute solution of the allergen which is injected into the skin and the ‘wheal’ that forms on the site is measured to gauge reaction to the allergen.
The patch test requires the person to wear a patch containing the suspected allergen for a couple of days and in this duration one would typically have to avoid bathing, swimming and so on.