Below is an instruction from Human. Write a response.
    ### Instruction:
    What is (are) Familial dermographism ?
    ### Response:
    Familial dermographism is a condition also known as skin writing. When people who have dermatographia lightly scratch their skin, the scratches redden into a raised wheal similar to hives. Signs and symptoms of dermatographia include raised red lines, swelling, inflammation, hive-like welts and itching.
    