The patches in McCune-Albright syndrome have jagged "coast of Maine" borders and are associated with endocrine dysfunction, unlike the unilateral patch with hypertrichosis of a Becker's nevus.
A typical café-au-lait macule is a uniformly pigmented, smooth-bordered patch that lacks the characteristic coarse hair growth (hypertrichosis) that develops within a Becker's nevus during puberty.
A CMN is a true mole (a proliferation of melanocytes) that is present at birth, whereas a Becker's nevus is a hamartoma that typically appears around puberty.
This is a bluish-grey patch on the lower back of infants that fades with time, differing in color, location, and natural history from a Becker's nevus.
This is a superficial fungal infection causing hypopigmented or hyperpigmented scaly patches that can be scraped off (positive KOH), unlike the stable, non-scaly patch of a Becker's nevus.
This pigmentation follows a prior inflammatory event or injury and typically fades over time, whereas a Becker's nevus is a persistent, primary lesion.
