This book suggests a new diagnostic approach to solve the myth of unexplainable pigmentations in the hidden area based on a clinicopathological study. The dilemma of of the three entities: Erythema Dyschromicum Perstans, Idiopathic Eruptive Macular Pigmentation and Lichen Planus Pigmentosus, finally resolved in a practical algorithmic approach that can be applied easily in the clinical practice.