Hairy Palm Sign

A term of art referring to the histologic changes on the palms of the hands of patients with picker’s nodule, in which the epidermal changes caused by constant rubbing—compact orthokeratosis, wedge-shaped hypergranulosis and variable hyperplasia—are present, but the dermal changes—widening of the papillary dermis and infundibulo-sebaceous-follicular units and pseudocarcinomatous hyperplasia—are not