Diagnosis of Asthma by Skin Test



If asthma is caused or, at least, suspected by some allergen, try to find out as to which of the allergens is the real causative factor and also what and when symptoms surfaced first; in which seasons symptoms aggravated. It is quite necessary to take a detailed history of the patient; taking into account the said points. One would be expected to undergo the following tests with the advise of a specialist.


Skin Tests

In order to detect presence of reagins (antibodies) which are present in the skin and blood, skin tests are called for. Union of antibody in the skin, with its corresponding antigen applied in the skin tests, causes the release either of histamine-like or histamine substance by the tissues and results in redness and a weal around the site.
Skin tests are performed with extracts of pollens, moulds, dusts, etc. While concluding or carrying out such tests, it must be ensured that extracts are processed in most appropriate method, are neither old, active or potent, have no pathogenic micro-organisms in them and have minimal amount of any antigen. The results will be more accurate and precise if the antigen extract retains more natural characteristics. When the extract is ready (after sterilization and stardization), skin tests are carried out either by:


• Scratch Test or " Intracutaneous test