The role of the ugly duckling sign in patient education

Abstract

The ABCDE (with A standing for asymmetry, B for border irregularity, C for color variegation, D for diameter larger than 6mm, and E for evolution) rule for melanoma (MM) recognition is widely taught in the general population. The ugly duckling (UD) sign is an alternate MM recognition strategy that is not generally taught. To compare the sensitivity, specificity, and accuracy of MM recognition with UD sign and the ABCD rule in a general population. Participants were randomized into either the ABCD or UD arm of the study. An educational tutorial on their respective teaching method followed. Participants were subsequently tested using images of 9 lesions (7 nevi and 2MMs) and asked to categorize each image as MM or not MM. A total of 51 participants were randomized to the ABCD group and 50 to the UD group. The sensitivity for MM recognition of both groups was similar. The specificity and accuracy for MM recognition was significantly higher (P =.02, P = .02) in the UD group. The E for evolution in the ABCDE rule was not tested. No follow-up knowledge retention test was conducted. The UD sign significantly improved accuracy and specificity of MM recognition. We recommend adding the UD sign to patient education in addition to the traditional ABCDE rule.