Skin tests
"At the moment we have a new way of immunotherapy, especially useful for children, which consists of applying drops under the tongue. This avoids punctures and can be applied at home".
DR. MARTA FERRER PUGA SPECIALIST. ALLERGY AND IMMUNOLOGY DEPARTMENT
Skin tests are a diagnostic method that consists of trying to reproduce an allergic reaction on the skin, thus succeeding in checking which substances one is allergic to.
The allergies take place when an allergen penetrates in the organism of an allergic subject, the immune system of this one responds producing a great amount of antibodies called immunoglobulin E (IgE).
The immunoglobulin is associated to the mast cells that, to the contact with the allergens, release some chemical mediators, among them the histamine that will produce the typical symptoms of the allergic reaction.
With the skin tests, the reaction that appears on the skin when the organism comes into contact with the substance to which one is allergic is detected.
When are skin tests indicated?
Allergy tests are useful to determine the agent that causes an individual's allergic reaction so that measures can be taken to avoid or limit exposure or to place the patient under drug treatment to control symptoms.
Most frequent indications of this test:
- Food allergies.
- Dust mite allergy.
- Drug allergy.
- Allergy to fungi.
- Pollen allergy.
Do you suspect you have any allergies?
You may need to have skin tests
How are skin tests performed?
The area where the punctures will be made (usually the forearm) is disinfected. Then, in a controlled order and separated a few centimeters from each other, drops of various solutions prepared with minute quantities of potentially allergenic substances (plant extracts, mites, pollens, insect poisons, food or medicine) are placed.
A needle or lancet is then pricked on top of each drop so that the solution penetrates the surface layer of the skin.
A period of 15 to 20 minutes is allowed to elapse, during which the skin will react selectively.
A positive reaction consists of a bean surrounded by an area of redness.
The result must always be compared with the controls applied, as the tests are always carried out with a positive control (histamine) and a negative one (physiological serum), so observing that a bean has been produced on the skin does not always mean being sensitive to something.
- Prick test: it consists of depositing a drop of the substance to be tested on the skin of the forearm and perforating the skin through the deposited drop with a lancet.
- Intradermal test: consists of injecting a small amount of substance into the most superficial layer of the skin.
The prick test has a minimal risk.
Only in cases of reactions to extremely serious allergens (anaphylaxis) certain precautions have to be taken, but for routine diagnosis they are practically without risk.
Where do we perform them?
IN NAVARRE AND MADRID
Department of Allergology
of the Clínica Universidad de Navarra
The Department of Allergy and Immunology of the Clinic is part of the Global Allergy and Asthma European Network, composed of the 25 best departments of Allergy in Europe, chosen for their scientific excellence, multidisciplinary work, teaching and international activities.
We have the most advanced diagnostic techniques, we are at the forefront of research and we collaborate with the best experts. We have more than 50 years of experience in the field.
What diseases do we treat?
Why at the Clinica?
- More than 50 years of experience.
- Pioneers in the technique of molecular diagnosis by microarray.
- Nursing specialized in allergic diseases and their care.
Our team of professionals
