Skin prick testing (SPT) is a reliable method to diagnose IgE-mediated allergic disease in patients with rhinoconjunctivitis, asthma, urticaria, anapylaxis, atopic eczema and suspected food and drug allergy. It provides evidence for sensitization and can help to confirm the diagnosis of a suspected type I allergy. It is minimally invasive, inexpensive, results are immediately available and when carried out by trained health professionals, reproducible. Since the first publication about SPT by Helmtraud Ebruster in 1959 who extensively researched this diagnostic test, it has been used as a primary diagnostic tool to detect type I hypersensitivity reactions.
SPT is indicated if a type I (immediate type) allergy is suspected, based on the medical history and clinical symptoms; they can identify sensitivity to inhalant, food or occupational allergens. SPTs thus provide objective confirmation of sensitivity, whereas the relevance of such sensitivity to allergens should always be carefully interpreted in the light of the clinical history so that appropriate advice concerning avoidance measures can be given and, as necessary, the correct allergen(s) prescribed for specific immunotherapy (SIT).
SPT is used to test adults and children from birth onwards. Repeated testing may be necessary in order to detect new sensitizations, especially in children, when symptoms change, or if new environmental allergens are suspected.
The chief advantage of SPT as compared to blood tests is that the test can be interpreted within 15 to 20 minutes after the reagent is applied to the skin. Moreover, the test gives a visual indication of the sensitivity which can be used in order to impact the patient’s behavior. SPT can also be utilized to test less common allergens, such as certain medications, and fresh fruits and vegetables where no specific IgE antibody measurements are available.
The test is performed in the OPD, with patient seated comfortably in a well lit room. The test is performed on the fore arms or the back. The procedure takes 45min to one hour, and results are interpreted in 15-20 mins. The maybe local discomfort in the area where test is performed, but it recovers in a short while. No other common side effects have been noted after these tests.
Immunotherapy treats the cause of allergies by giving small doses of what a person is allergic to, which increases “immunity” or tolerance to the allergen and reduces the allergic symptoms.
Sublingual immunotherapy is administered at home without any injections. The patient takes drops under the tongue daily. During the first four months, called the escalation phase, the dosage is gradually increased. After that, in the maintenance phase, the patient takes the same dose of drops each day.
t has not seen to cause any major side effects. Slight increase in allergic symptoms maybe seen during initial phase. Local irritation in sublingual area maybe seen.