
A drop of a solution containing a possible allergen is placed on the skin. Then a series of scratches or needle pricks lets the solution enter the skin. If the skin gets a red, raised itchy area (called a wheal), it usually means that the person is allergic to that allergen.
| By | Healthwise Staff |
| Primary Medical Reviewer | E. Gregory Thompson, MD - Internal Medicine |
| Specialist Medical Reviewer | Rohit K Katial, MD - Allergy and Immunology |
| Last Revised | June 30, 2011 |