Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Unna-Thost palmoplantar keratoderma ?
    ### Response:
    Unna-Thost palmoplantar keratoderma is a type of diffuse palmoplantar keratoderma that mostly affects the palms of the hands and soles of the feet. It usually begins in early childhood with redness of the palms and soles. The palms and soles gradually become thicker and develop a yellowish, waxy appearance.
    