Allergology and immunology outpatient service
Allergies are at endemic levels these days. Allergy is basically the immune system’s overreaction to otherwise harmless stimuli such as pollens, food substances, and animal dander. Usually, the allergic reaction gradually intensifies; early signs include rashes or a runny nose and sneezing, which might turn into asthma or, occasionally, severe anaphylactic shock if untreated. Allergy can severely compromise an individual’s quality of life; sometimes, life-threatening reactions may also develop.
The most common allergic diseases include:
- asthma of allergic origin
- hives of allergic origin, occasionally accompanied by angioedema (fluid accumulation affecting the face and airways)
- anaphylactic shock (fulminant allergic reaction to e.g. insect bites, penicillin, some foods)
- food allergy
- contact allergy, eczema
- hay fever (both seasonal and perennial)
Allergy tests are done to find out what airborne allergens (hay fever, asthma), food allergens (hives) or contact allergens (eczema) are at work to provoke the patient’s allergic symptoms.
This procedure is capable of detecting the immediate type allergic reaction, which plays a role in the development of hives, asthma, and hay fever. The test is quick, and safe when done by a qualified doctor.
The procedure involves a drop of one or more allergic substances being placed on the forearm skin, then carefully pricked to penetrate under the keratic layer. If the subject is allergic to the substance thus introduced, a small wheal, an itchy bump will appear at the prick site. Assessment takes place 15 minutes after pricking.
The test is recommended above 3 years of age, on healthy skin. Areas with eczema or infection should not be subjected to allergy tests. Prior to the procedure, the examining physician must be told about regularly or occasionally taken medication because these might interfere with the results of the test! It is important to know that false negative (the subject is in fact allergic to the substance but the test fails to detect this; a possible outcome e.g. when taking antiallergic medication) or false positive (the subject is not allergic to the substance that provoked the reaction; e.g. in a patient with atopic eczema, the procedure itself may evoke a reaction) results are possible.
No prick test must be done when severe allergic symptoms are ongoing or only stopped very recently, in infectious conditions with fever, in a severe asthmatic state, or during any other acute illness. It must not be done on skin areas affected by abnormalities or sunburn either.