Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) mal de Meleda ?
    ### Response:
    Mal de Meleda is a rare skin disorder that begins in early infancy. Affected individuals have a condition known as palmoplantar keratoderma, in which the skin of the palms of the hands and soles of the feet becomes thick, hard, and callused. In mal de Meleda, the thickened skin is also found on the back of the hands and feet and on the wrists and ankles.
    