Pricktest

A pricking test, commonly called a skin prick test (SPT), is a diagnostic procedure used to identify IgE-mediated sensitizations to a range of allergens. It is widely used in evaluating suspected allergic rhinitis, asthma, atopic dermatitis, food allergies, and venom allergies. The test helps to determine which allergens may be contributing to a patient’s symptoms and can guide avoidance strategies and treatment decisions.

During the procedure, small amounts of standardized allergen extracts are applied to the surface of the forearm or back. The skin is then lightly pricked or scratched through each drop with a sterile lancet. After about 15 minutes, the test area is examined for a wheal (a raised bump) and a surrounding flare. A histamine-containing solution serves as a positive control and a saline solution as a negative control. A wheal, typically larger than the negative control, indicates sensitization to the tested allergen. Results are interpreted in the context of the patient’s clinical history and may vary by laboratory criteria.

Preparation for testing usually includes avoiding certain medications that suppress skin reactions, such as nonsedating antihistamines, for several days before the test. The test is generally safe but may cause itching and local swelling; rare systemic reactions can occur, so it is performed in a setting equipped to manage anaphylaxis.

Limitations include that a positive test shows sensitization, not clinical allergy, and results can be influenced by skin conditions, medications, or recent infections. The prick test is often complemented by patient history and, when indicated, by other tests such as serum-specific IgE testing or oral food challenges.