Skin Prick Test

A skin prick test (SPT) can be used to measure allergic sensitization in the skin. Mast cells that are present in the skin are loaded with IgE from the patient. When an allergen is pricked into the skin, the mast cells can degranulate immediately, and induce swelling and redness of the skin. The SPT is performed using a 1 mm-tip lancet to prick the allergen solution into the skin. The skin response is analyzed after 15-20 minutes by scoring redness and swelling. The wheal area of the skin response in perpendicular diameter in mm or surface area in mm2 is used to measure the extent of the response