PLC presents as small, reddish-brown papules with an adherent mica-like scale that can be detached to reveal a shiny surface, a different morphology than the pink, scaly papules of guttate psoriasis.
This is distinguished by its initial, larger "herald patch," followed by an eruption of smaller oval plaques arranged in a "Christmas tree" pattern on the back, with the long axis of lesions following skin lines.
The rash of secondary syphilis can be papulosquamous, but it is distinguished by its frequent involvement of the palms and soles and can be confirmed with serologic testing.
