Kenny Y C Kwong, Tiffany Jean and Nasser Redjal
Epicutaneous skin testing for sensitization to aero-allergens in patients with allergic diseases requires measurement of skin wheal and erythema in response to antigens. This may be variable between different providers especially among patients with dark skin pigmentation. Purpose of this study is to determine whether Allergy-Immunology specialists vary in their measurement of epicutaneous skin tests in patients with differential skin pigmentation. 3 patients with differing skin tones were skin tested using various concentrations of histamine to produce increasing sizes of skin wheal and erythema reaction. High quality photographs of these were taken and sent to 20 board certified/eligible Allergy-Immunologists to measure the wheal and erythema size. There was poor agreement among specialists in measurement of both wheal and flare sizes from patient with darkest skin tone. In contrast in patients with lighter skin tones there was fair to good agreement and excellent agreement from specialists in measurement of wheal and flare sizes respectively. Measurement of skin test results in patients with dark skin pigmentation may have significant variability even among specialists and in vitro tests may be more appropriate in these patients.