The ABCDE Rule originally described by Friedman et al. it is now included in The American Cancer Society’s The Seven Warning Signals of Cancer and is a simple method that allows you to identify a nevus at risk.
This method takes into account the macroscopic characteristics of a nevus. If two or more parameters are identifiable on the nevus, it can be considered at risk. It is therefore believed that it is an easy-to-apply method that allows the general practitioner or often the patient himself to identify nevi at risk to be subjected to dermatological evaluation.
A: asymmetry (ideally dividing a nevus in half, the two halves appear different from each other)
B: irregular border with indentations, introflections and/or extroflections
C: presence of multiple colors in a nevus (brown, black, blue, red, white, pink)
D: diameter greater than 6 mm
E: evolution: refers to a nevus that changes in the short term (itching, bleeding, erythematous halo, desquamation)